Electroluminescent device

ABSTRACT

The present invention relates to an electronic device, especially an electroluminescent devices, comprising a compound of Formula (I), especially as host for phosphorescent compounds. The hosts may function with phosphorescent materials to provide improved efficiency, stability, manufacturability, or spectral characteristics of electroluminescent devices.

The present invention relates to an electronic device, especially anelectroluminescent devices, comprising a compound of the formula

especially as host for phosphorescent compounds. The hosts may functionwith phosphorescent materials to provide improved efficiency, stability,manufacturability, or spectral characteristics of electroluminescentdevices.

JP2007223921 relates to compounds of formula

Q=

(R₁-R₆═H, Q≧1 of R₁-R₆=Q; X₁-X₅═H, C₁₋₁₀alkyl, aryl, SiRaRbRc≧1 ofX₁-X₅═SiRaRbRc; Ra, Rb, Rc=H, OH, C₁₋₁₀alkyl, alkoxy, aryl), which areuseful as electron-transporting layer, host materials, etc., for org.electroluminescent devices.

KR2007102243 is directed to triphenylene derivs. of formula

(R₁-R₄ are H, C₁-C₁₀alkyl or alkoxyl, halogen, cyano group, nitro group,etc.). The triphenylene derivs. have high glass transition temp., andcan be used as luminous materials of org. light-emitting diode.

KR2006107720 relates to a triphenylene derivative which has a high glasstransition temperature and is excellent in thermal stability, and anorganic light emitting diode containing the triphenylene derivative as ahole injection material, a hole transfer material or a light emittinglayer material. The triphenylene derivative is represented by theformula

wherein R₁ and R₂ are a substituted or unsubstituted C₆-C₁₄aryl group.

JP11092420 relates to triphenylene derivatives of the formula

wherein Ar₁ to Ar₆ are each an aryl or the like; R₁₁ to R₁₆ are eachformula

(R₁ to R₃ are each, for example, H); R₂₁ to R₂₆ are each, for example,an alkyl; m1-m6 are each 0 or 1; n1-n6 are each 0, 1, or 2, which areuseful as a liquid crystalline material. The following compounds areexplicitly disclosed:

R═Cl, Br, or F.

JP11251063 discloses triphenylene compounds expressed by the formula

such as, for example,

which are used as a component material of an organic EL element. In theformula, R₁ to R₁₂ each independently represent an hydrogen atom, ahalogen atom, a hydroxyl group, a substituted or unsubstituted aminogroup, a nitro group, a cyano group, a substituted or unsubstitutedalkyl group, a substituted or unsubstituted alkenyl group, a substitutedor unsubstituted cycloalkyl group, a substituted or unsubstituted alkoxygroup, a substituted or unsubstituted aromatic hydrocarbon group, asubstituted or unsubstituted aromatic heterocycle group, a substitutedor unsubstituted aralkyl group, a substituted or unsubstituted aryloxygroup, a substituted or unsubstituted alkoxycarbonyl group, or acarboxyl group. R₁ to R₁₂ may form two rings out of them.

JP2005259472 relates to an organic electroluminescent element which hasan organic layer including a mutually adjoining luminous layer and ablock layer between a pair of electrodes and contains a phosphorescentmaterial in the luminous layer, and contains triphenylene compound inthe block layer.

Explicitly disclosed examples of the triphenylene compound, such as

include at least two triphenyl groups, which are unsubstituted.

U.S. Pat. No. 6,492,041 relates to an organic electroluminescent (EL)device comprising an anode, a cathode and at least one organic thin-filmlayer disposed between said anode and said cathode, said one or morethan one organic thin-film layers include a luminescent layer, said oneor at least one of said more than one organic thin-film layers include acompound expressed by general formula [1]:

wherein each of R₁ to R₁₂ independently represents hydrogen atom,halogen atom, hydroxyl group, substituted or non-substituted aminogroup, nitro group, cyano group, substituted or non-substituted alkylgroup, substituted or non-substituted or non-substituted alkenyl group,substituted or non-substituted cycloalkyl group, substituted ornon-substituted alkoxy group, substituted or non-substituted aromatichydrocarbon, substituted or non-substituted aromatic heterocyclic group,substituted or non-substituted aralkyl group, substituted ornon-substituted aryloxy group, substituted or non-substitutedalkoxycarbonyl group, or carboxyl group, and wherein each of R₁ to R₁₂may be a ring formed by two of said atoms and groups and at least one ofR₁ to R₁₂ is a diarylamino group expressed by —NAr₁Ar₂, each of Ar₁ andAr₂ independently representing an aryl group having 6-20 carbons, one ofAr₁ and Ar₂ having a substituted or non-substituted styryl group as asubstituent group and the other of the Ar₁ and Ar₂ having no substitutedor non-substituted styryl group as a substituent group. The compounds ofgeneral formula [1] are used as hole transport material.

JP2006143845 relates to compounds of formula

wherein Z₁, Z₂ are an aromatic hydrocarbon ring, aromatic heterocyclicring; R₁ to R₃ are H, or substituent; n1=0 to 3; n2, n3=0 to 4;L1=linkage group, single bond), such as, for example,

The compounds show high luminescence efficiency and long life.

WO2006038709 compounds represented by the general formula

wherein R₁ to R₆ are each independently hydrogen or substituentrepresented by the general formula —C≡CSiRaRbRc, with the proviso thatat least one of R₁ to R₆ is a substituent represented by the generalformula —C≡SiRaRbRc, wherein Ra, Rb, Rc are each independently an C₁-C₁₀aliphatic hydrocarbon group or aromatic hydrocarbon group. The compoundsare prepared by coupling of halogenated triphenylene compds.

(X₁ to X₆ are each independently H, Br, or iodo, with the proviso thatat least one of X1-X6 is Br or iodo) with a silylacetylene of generalformula HC≡C SiRaRbRc (Ra, Rb, Rc=same as above). An organicelectroluminescent device comprising a luminescent layer containing atleast one of compounds of formula

and a phosphorescent dopant is also disclosed. A compound of formula

is explicitly disclosed, wherein X₁ to X₆ are each Br.

US2005025993 relates to electroluminescent devices which comprise ananode; a cathode; a first organic layer disposed between the anode andthe cathode, where the first organic layer comprises a material thatproduces phosphorescent emission when a voltage is applied between theanode and the cathode; and a second organic layer disposed between thefirst organic layer and the cathode, where the second organic layer isin direct contact with the first organic layer, and where the secondorganic layer comprises a non-heterocyclic aromatic hydrocarbonmaterial, such as, for example,

JP2006104124 relates to compounds represented by the general formula

wherein R₁-R₆ are each independently hydrogen or substituent representedby the general formula —C≡CSiRaRbRc, with the proviso that at least oneof R₁-R₆ is a substituent represented by the general formula—C≡CSiRaRbRc, wherein Ra, Rb, Rc are each independently C₁₋₁₀aliphatichydrocarbon group or aromatic hydrocarbon group. An organicelectroluminescent device possessing a luminescent layer containing atleast one of compounds I and a phosphorescent dopant is also disclosed.

WO2006047119 (US2006/0088728) relates to a device, comprising: an anode;a cathode; an emissive layer disposed between the anode and the cathode,wherein the emissive layer comprises a host and a dopant, and whereinthe host material is selected from the group consisting of:

wherein each R represent no substitution, mono-, di-, ortri-substitution, and wherein the substituents are the same ordifferent, and each is selected from the group consisting of alkyl,alkenyl, alkynyl, aryl, thioalkoxy, halo, haloalkyl, cyano, carbonyl,carboxyl, heteroaryl and substituted aryl, and wherein at least one Rfor each Compounds I, II, III, or IV includes a carbazole group.

The following compounds are explicitly disclosed in WO2006047119:

WO2006130598 relates to an emissive layer comprising a phosphorescentmaterial and a triphenylene compound having the formula

wherein R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈, R₉, R₁₀, R₁₁ and R₁₂ is eachindependently H or a substituent selected from the group consisting ofaryl, substituted aryl, heteroaryl, substituted heteroaryl, alkyl,arylkyl, heteroalkyl, alkenyl, and alkynyl; and wherein the triphenylenecompound has at least two substituents and a molecular weight of lessthan 1400. In the compounds, which are preferred and which areexplicitly disclosed by means of examples, at least one of R⁹ and R¹² ishydrogen.

US2007087223 relates to dibenzoanthracene derivatives substituted by anamino compound group at least one of 9-position and 14-position of adibenzo[a,c]anthracene skeleton and represented by the following formula(1) or (2):

wherein:

X¹, X² and X each independently represents a substituted orunsubstituted arylene group or a substituted or unsubstituted divalentheterocyclic group;

A, B, D and D′ each independently represents a substituted orunsubstituted alkyl group, a substituted or unsubstituted aryl group ora substituted or unsubstituted heterocyclic group, and between theadjacent groups, may be fused together to form rings; and

Y¹ to Y¹² and R¹ each independently represents a hydrogen atom, ahalogen atom, a substituted or unsubstituted alkyl group, an alkoxygroup, a substituted or unsubstituted aryl group, or a substituted orunsubstituted heterocyclic group, and, when Y¹ to Y¹² and R¹ are otherthan a hydrogen atom or a halogen atom, Y¹ to Y¹² and R¹ may be fusedtogether between the adjacent groups to form rings. Thedibenzoanthracene derivatives are used as light-emitting material.

Notwithstanding these developments, there remains a need for EL devicescomprising new host materials, and especially hosts that will functionwith phosphorescent materials to provide improved efficiency, stability,manufacturability, and/or spectral characteristics of electroluminescentdevices.

Accordingly, the present invention provides an electronic device,especially an EL device, comprising a compound of the formula

especially

wherein R¹ and R² are independently of each other a C₆-C₂₄aryl group, ora C₂-C₃₀heteroaryl group, which can optionally be substituted,

R³ and R⁴ are independently of each other hydrogen, a C₁-C₂₅alkyl group,a C₆-C₂₄aryl group, or a C₂-C₃₀heteroaryl group, which can optionally besubstituted,

X¹ is

—NA¹A^(1′), —P(═O)A⁴A^(4′), —SiA⁶A⁷A⁸, a C₁₀-C₂₈aryl group, which canoptionally be substituted, or a C₂-C₃₀heteroaryl group, especially anelectron deficient heteroaryl group, which can optionally besubstituted,

X² is

—NA²A^(2′), —P(═O)A⁵A^(5′), or —SiA^(6′)A^(7′)A^(8′), a C₁₀-C₂₈arylgroup, which can optionally be substituted, or a C₂-C₃₀heteroaryl group,especially an electron deficient heteroaryl group, which can optionallybe substituted,

Ar and Ar′ are independently of each other C₆-C₁₄aryl, such as phenyl,or naphthyl, which may optionally be substituted by one or more groupsselected from C₁-C₂₅alkyl, which may optionally be interrupted by —O—,or C₁-C₂₅alkoxy,

L¹ and L² are independently of each other a single bond, or a bridgingunit BU, such as

R⁵ and R⁶ are independently of each other halogen, or an organicsubstituent, or

R⁵ and R⁶, which are adjacent to each other, together form an aromatic,or heteroaromatic ring, or ring system, which can optionally besubstituted,

A¹, A², A^(1′) and A^(2′) are independently of each other a C₆-C₂₄arylgroup, a C₂-C₃₀heteroaryl group, which can optionally be substituted, or

A¹ and A^(1′) or A² and A^(2′) or A³ and A^(3′) together with thenitrogen atom to which they are bonded form a heteroaromatic ring, orring system, such as

m′ is 0, 1, or 2;

A⁴, A^(4′), A⁶, A⁷, A⁸, A⁵, A^(5′), A^(6′), A^(7′), and A^(8′) areindependently of each other a C₆-C₂₄aryl group, or a C₂-C₃₀heteroarylgroup, which can optionally be substituted,

m1 can be the same or different at each occurrence and is 0, 1, 2, 3, or4, especially 0, 1, or 2, very especially 0 or 1,

R¹¹⁹ and R¹²⁰ are independently of each other C₁-C₁₈alkyl, C₁-C₁₈alkylwhich is substituted by E and/or interrupted by D, C₆-C₂₄aryl,C₆-C₂₄aryl which is substituted by G, C₂-C₂₀heteroaryl, C₂-C₂₀heteroarylwhich is substituted by G, C₂-C₁₈alkenyl, C₂-C₁₈alkynyl, C₁-C₁₈alkoxy,C₁-C₁₈alkoxy which is substituted by E and/or interrupted by D, orC₇-C₂₅aralkyl, or

R¹¹⁹ and R¹²⁰ together form a group of formula ═CR¹²¹R¹²², wherein

R¹²¹ and R¹²² are independently of each other H, C₁-C₁₈alkyl,C₁-C₁₈alkyl which is substituted by E and/or interrupted by D,C₆-C₂₄aryl, C₆-C₂₄aryl which is substituted by G, or C₂-C₂₀heteroaryl,or C₂-C₂₀heteroaryl which is substituted by G, or

R¹¹⁹ and R¹²⁰ together form a five or six membered ring, whichoptionally can be substituted by C₁-C₁₈alkyl, C₁-C₁₈alkyl which issubstituted by E and/or interrupted by D, C₆-C₂₄aryl, C₆-C₂₄aryl whichis substituted by G, C₂-C₂₀heteroaryl, C₂-C₂₀heteroaryl which issubstituted by G, C₂-C₁₈alkenyl, C₂-C₁₈alkynyl, C₁-C₁₈alkoxy,C₁-C₁₈alkoxy which is substituted by E and/or interrupted by D,C₇-C₂₅aralkyl, or —C(═O)—R¹²⁷, and

R¹²⁷ is H; C₆-C₁₈aryl; C₆-C₁₈aryl which is substituted by C₁-C₁₈alkyl,or C₁-C₁₈alkoxy; C₁-C₁₈alkyl; or C₁-C₁₈alkyl which is interrupted by—O—,

D is —CO—, —COO—, —S—, —SO—, —SO₂—, —O—, —NR⁶⁵—, —SiR⁷⁰R⁷¹—, —POR⁷²—,—CR⁶³═CR⁶⁴—, or —C≡C—, and

E is —OR⁶⁹, —SR⁶⁹, —NR⁶⁵R⁶⁶, —COR⁶⁸, —COOR⁶⁷, —CONR⁶⁵R⁶⁶, —CN, orhalogen,

G is E, or C₁-C₁₈alkyl,

R⁶³ and R⁶⁴ are independently of each other C₆-C₁₈aryl; C₆-C₁₈aryl whichis substituted by C₁-C₁₈alkyl, C₁-C₁₈alkoxy; C₁-C₁₈alkyl; or C₁-C₁₈alkylwhich is interrupted by —O—; or

R⁶⁵, R^(65′) and R⁶⁶ are independently of each other C₆-C₁₈aryl;C₆-C₁₈aryl which is substituted by C₁-C₁₈alkyl, C₁-C₁₈alkoxy;C₁-C₁₈alkyl; or C₁-C₁₈alkyl which is interrupted by —O—; or

R⁶⁵ and R⁶⁶ together form a five or six membered ring,

R⁶⁷ is C₆-C₁₈aryl; C₆-C₁₈aryl which is substituted by C₁-C₁₈alkyl, orC₁-C₁₈alkoxy; C₁-C₁₈alkyl; or C₁-C₁₈alkyl which is interrupted by —O—,

R⁶⁸ is H; C₆-C₁₈aryl; C₆-C₁₈aryl which is substituted by C₁-C₁₈alkyl, orC₁-C₁₈alkoxy; C₁-C₁₈alkyl; or C₁-C₁₈alkyl which is interrupted by —O—,

R⁶⁹ is C₆-C₁₈aryl; C₆-C₁₈aryl, which is substituted by C₁-C₁₈alkyl,C₁-C₁₈alkoxy; C₁-C₁₈alkyl; or C₁-C₁₈alkyl which is interrupted by —O—,

R⁷⁰ and R⁷¹ are independently of each other C₁-C₁₈alkyl, C₆-C₁₈aryl, orC₆-C₁₈aryl, which is substituted by C₁-C₁₈alkyl, and

R⁷² is C₁-C₁₈alkyl, C₆-C₁₈aryl, or C₆-C₁₈aryl, which is substituted byC₁-C₁₈alkyl;

R⁴¹ can be the same or different at each occurrence and is Cl, F, CN,NR⁴⁵R^(45′), a C₁-C₂₅alkyl group, a C₄-C₁₈cycloalkyl group, aC₁-C₂₅alkoxy group, in which one or more carbon atoms which are not inneighbourhood to each other could be replaced by —NR⁴⁵—, —O—, —S—,—C(═O)—O—, or —O—C(═O)—O—, and/or wherein one or more hydrogen atoms canbe replaced by F, a C₆-C₂₄aryl group, or a C₆-C₂₄aryloxy group, whereinone or more carbon atoms can be replaced by O, S, or N, and/or which canbe substituted by one or more non-aromatic groups R⁴¹, or two or moregroups R⁴¹ form a ring system;

R⁴⁵ and R^(45′) are independently of each other a C₁-C₂₅alkyl group, aC₄-C₁₈cycloalkyl group, in which one or more carbon atoms which are notin neighbourhood to each other could be replaced by —NR^(45″)—, —O—,—S—, —C(═O)—O—, or, —O—C(═O)—O—, and/or wherein one or more hydrogenatoms can be replaced by F, a C₆-C₂₄aryl group, or a C₆-C₂₄aryloxygroup, wherein one or more carbon atoms can be replaced by O, S, or N,and/or which can be substituted by one or more non-aromatic groups R⁴¹,

R^(45″) is a C₁-C₂₅alkyl group, or a C₄-C₁₈cycloalkyl group, and

m can be the same or different at each occurrence and is 0, 1, 2, or 3,especially 0, 1, or 2, very especially 0 or 1.

In addition, the present invention relates to compounds of the formula

especially

wherein X¹, X², R¹, R², R³, R⁴, R⁵, R⁶ and m are as defined above.

The compounds the present invention tend to be amorphous in solid stateand, hence, can be processed either by sublimation, or from solution.

The electronic device of the present invention is preferably anelectroluminescent (EL) device. The compounds of formula I can be usedin organic light emitting diodes (OLEDs) as hosts for phosphorescentcompounds. Accordingly, the present invention also provideselectroluminescent devices comprising the compounds of formula I,especially an electroluminescent device comprising a cathode, an anode,and therebetween a light emitting layer containing a host material and aphosphorescent light-emitting material wherein the host material is acompound of formula I. In addition, the compounds of formula I may beused as hole, or electron blocking material and/or hole, or electrontransport material.

Preferably, the compound of formula I is a compound of formula:

especially a compound according of formula

The compounds of the present invention are characterized in that R¹ andR² are a C₆-C₂₄aryl group, or a C₂-C₃₀heteroaryl group, which canoptionally be substituted. Preferably, R¹ and R² area C₆-C₂₄aryl group,which can optionally be substituted, such as

wherein R⁷, R⁸ and R⁹ are independently of each other H, C₁-C₁₈alkyl,C₁-C₁₈alkoxy, or C₁-C₁₈alkyl which is interrupted by O.

In a preferred embodiment of the present invention R¹ and R² are aC₆-C₂₄aryl group, which can optionally be substituted, and R³ ishydrogen and R⁴ is a C₁-C₂₅alkyl group, or a C₆-C₂₄aryl group, which canoptionally be substituted, or R³ and R⁴ are a C₆-C₂₄aryl group, whichcan optionally be substituted. Examples of a C₆-C₂₄aryl group, which canoptionally be substituted, are

wherein R⁷, R⁸ and R⁹ are as defined above.

In another preferred embodiment of the present invention R¹ and R² are aC₂-C₃₀heteroaryl group, which can optionally be substituted, and R³ ishydrogen and R⁴ is a C₂-C₃₀heteroaryl group, which can optionally besubstituted, or R³ and R⁴ are a C₂-C₃₀heteroaryl group, which canoptionally be substituted. Examples of a C₂-C₃₀heteroaryl group, whichcan optionally be substituted, are compounds of formula

wherein R⁷, R⁸ and R⁹ are as defined above.

Examples of L¹ and L² are a single bond, —(CR⁴⁷═CR⁴⁸)_(m2)—,—(Ar³)_(m3)—, —[Ar³(Y¹)_(m5)]_(m4)—, —[(Y¹)_(m5)Ar³]_(m4)—, or—[Ar³(Y²)_(m5)Ar⁴]_(m4)—, wherein Y¹, Y², R⁴⁷, R⁴⁸, Ar³, Ar⁴, m2, m3, m4and m5 are as defined below. Preferably, L¹ and L² are a single bond, ora bridging unit BU of formula

Examples of -L¹-X¹ and -L²-X² are

wherein R²⁰⁰ is C₁-C₂₅alkyl, which may optionally be interrupted by —O—,or C₁-C₂₅alkoxy;

wherein R¹¹⁶ and R¹¹⁷ are as defined below. -L¹-X¹ is preferably a group

or —NA¹A^(1′). -L²-X² is preferably a group

or —NA²A^(2′). X¹ and X² may be different, but are preferably the same.

In a preferred embodiment -L¹-X¹ and -L²-X² are independently of eachother a group of formula

—NA¹A^(1′), or a group

wherein A¹, A^(1′), A³ and A^(3′) are independently of each other aC₆-C₂₄aryl group, or a C₂-C₃₀heteroaryl group, which can optionally besubstituted, especially phenyl, naphthyl, anthryl, biphenylyl,2-fluorenyl, phenanthryl, or perylenyl, which can optionally besubstituted, such as

or A¹ and A^(1′), or A³ and A^(3′) together with the nitrogen atom towhich they are bonded form a heteroaromatic ring, or ring system, suchas

m′ is 0, 1, or 2;

m1 can be the same or different at each occurrence and is 0, 1, 2, 3, or4, especially 0, 1, or 2, very especially 0 or 1;

R¹¹⁶, R¹¹⁷ and R^(117′) are independently of each other H, halogen, —CN,C₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by E and/or interrupted byD, C₆-C₂₄aryl, C₆-C₂₄aryl which is substituted by G, C₂-C₂₀heteroaryl,C₂-C₂₀heteroaryl which is substituted by G, C₂-C₁₈alkenyl,C₂-C₁₈alkynyl, C₁-C₁₈alkoxy, C₁-C₁₈alkoxy which is substituted by Eand/or interrupted by D, C₇-C₂₅aralkyl, —C(═O)—R¹²⁷, —C(═O)OR¹²⁷, or—C(═O)NR¹²⁷R¹²⁶, or

substituents R¹¹⁶, R¹¹⁷ and R^(117′), which are adjacent to each other,can form a ring,

R¹¹⁹ and R¹²⁰ are as defined above,

R¹²⁶ and R¹²⁷ are independently of each other H; C₆-C₁₈aryl; C₆-C₁₈arylwhich is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; C₁-C₁₈alkyl; orC₁-C₁₈alkyl which is interrupted by —O—,

BU is

wherein R⁴¹ is as defined above and m1 is as defined above; or -L¹-X¹and -L²-X² are independently of each other a group

wherein

R¹¹⁶, R^(116′), R¹¹⁷ and R^(117′) are independently of each other H,halogen, —CN, C₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by E and/orinterrupted by D, C₆-C₂₄aryl, C₆-C₂₄aryl which is substituted by G,C₂-C₂₀heteroaryl, C₂-C₂₀heteroaryl which is substituted by G,C₂-C₁₈alkenyl, C₂-C₁₈alkynyl, C₁-C₁₈alkoxy, C₁-C₁₈alkoxy which issubstituted by E and/or interrupted by D, C₇-C₂₅aralkyl, —C(═O)—R¹²⁷,—C(═O)OR¹²⁷, or —C(═O)NR¹²⁷R¹²⁶, or substituents R¹¹⁶, R^(116′), R¹¹⁷and R^(117′), which are adjacent to each other, can form a ring,

R¹²⁶ and R¹²⁷ are independently of each other H; C₆-C₁₈aryl; C₆-C₁₈arylwhich is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; C₁-C₁₈alkyl; orC₁-C₁₈alkyl which is interrupted by —O—, and

D, E and G are as defined above; or -L¹-X¹ and -L²-X² are independentlyof each other a group

wherein R¹¹⁶, R¹¹⁷ and R^(117′) are as defined above.

Even more preferred are compounds of the formula (I), wherein -L¹-X¹ and-L²-X² are independently of each other a group of formula

—NA¹A^(1′), or a group

wherein

A¹, A^(1′), A³ and A^(3′) are independently of each other

or A³ and A^(3′) together with the nitrogen atom to which they arebonded form a group of formula

R¹¹⁶ and R¹¹⁷ are independently of each other C₁-C₂₅alkyl, which mayoptionally be interrupted by —O—, or C₁-C₂₅alkoxy;

BU is

wherein R⁴¹ can be the same or different at each occurrence and isC₁-C₂₅alkyl, which may optionally be interrupted by —O—, orC₁-C₂₅alkoxy; m1 is 0, 1, or 2.

Preferably, R¹¹⁶, R^(116′), R¹¹⁷ and R^(117′) are independently of eachother H, C₁-C₁₂alkyl, such as methyl, ethyl, n-propyl, iso-propyl,n-butyl, isobutyl, sec-butyl, t-butyl, 2-methylbutyl, n-pentyl,isopentyl, n-hexyl, 2-ethylhexyl, or n-heptyl, C₁-C₁₂alkyl which issubstituted by E and/or interrupted by D, such as —CH₂OCH₃, —CH₂OCH₂CH₃,—CH₂OCH₂CH₂OCH₃, or —CH₂OCH₂CH₂OCH₂CH₃, C₆-C₁₄aryl, such as phenyl,naphthyl, or biphenylyl, C₅-C₁₂cycloalkyl, such as cyclohexyl,C₆-C₁₄aryl which is substituted by G, such as —C₆H₄OCH₃, —C₆H₄OCH₂CH₃,—C₆H₃(OCH₃)₂, or —C₆H₃(OCH₂CH₃)₂, —C₆H₄CH₃, —C₆H₃(CH₃)₂, —C₆H₂(CH₃)₃, or—C₆H₄tBu.

Preferably, R¹¹⁹ and R¹²⁰ are independently of each other C₁-C₁₂alkyl,such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, hexyl,octyl, or 2-ethyl-hexyl, C₁-C₁₂alkyl which is substituted by E and/orinterrupted by D, such as —CH₂(OCH₂CH₂)_(w)OCH₃, w=1, 2, 3, or 4,C₆-C₁₄aryl, such as phenyl, naphthyl, or biphenylyl, C₆-C₁₄aryl which issubstituted by G, such as —C₆H₄OCH₃, —C₆H₄OCH₂CH₃, —C₆H₃(OCH₃)₂,—C₆H₃(OCH₂CH₃)₂, —C₆H₄CH₃, —C₆H₃(CH₃)₂, —C₆H₂(CH₃)₃, or —C₆H₄tBu, orR¹¹⁹ and R¹²⁰ together form a 4 to 8 membered ring, especially a 5 or 6membered ring, such as cyclohexyl, or cyclopentyl, which can optionallybe substituted by C₁-C₈alkyl.

D is preferably —CO—, —COO—, —S—, —SO—, —SO₂—, —O—, —NR⁶⁵—, wherein R⁶⁵is C₁-C₁₂alkyl, such as methyl, ethyl, n-propyl, iso-propyl, n-butyl,isobutyl, or sec-butyl, or C₆-C₁₄aryl, such as phenyl, naphthyl, orbiphenylyl.

E is preferably —OR⁶⁹; —SR⁶⁹; —NR⁶⁵R⁶⁵; —COR⁶⁸; —COOR⁶⁷; —CONR⁶⁵R⁶⁵; or—CN; wherein R⁶⁵, R⁶⁷, R⁶⁸ and R⁶⁹ are independently of each otherC₁-C₁₂alkyl, such as methyl, ethyl, n-propyl, iso-propyl, n-butyl,isobutyl, sec-butyl, hexyl, octyl, or 2-ethyl-hexyl, or C₆-C₁₄aryl, suchas phenyl, naphthyl, or biphenylyl, which may optionally be substituted.

G has the same preferences as E, or is C₁-C₁₈alkyl, especiallyC₁-C₁₂alkyl, such as methyl, ethyl, n-propyl, iso-propyl, n-butyl,isobutyl, sec-butyl, hexyl, octyl, or 2-ethyl-hexyl.

Examples of

(m′=2), wherein R⁴¹ is H, or C₁-C₁₈alkyl.

Examples of groups

are shown below:

wherein R⁴¹, R¹¹⁶, R¹¹⁷, R¹¹⁹, R¹²⁰ and m are as defined above.

In another preferred embodiment of the present invention X¹ and X²are anelectron deficient heteroaryl group.

The term “electron deficient heteroaryl group” means a group in whichthe isolated (unconnected) electron deficient heteroaryl unit has a HOMOof −5.3 eV or lower. Preferably at least one of X¹ and X², morepreferably both of X¹ and X² are an electron deficient heteroaryl group.

The HOMO and LUMO energy levels for organic materials to be used inOLEDs have been estimated in several ways. The two common methods forestimating HOMO levels are solution electrochemistry and ultravioletphotoelectron spectroscopy (UPS). The most common method for determiningoxidation and reduction potentials is cyclic voltametry, whereas theanalyte or compound which corresponds to the group is dissolved with ahigh concentration of electrolyte. Electrodes are inserted and thevoltage scanned in either the positive or negative direction (dependingon whether an oxidation or reduction is performed). The presence of aredox reaction is indicated by current flowing through the cell. Thevoltage scan is then reversed and the redox reaction is reversed. If theareas of the two redox waves are the same the process is reversible. Thepotential at which these events occur give the value of the reduction oroxidation potential relative to a reference. The reference can be anexternal one, such as Ag/AgCl or SCE, or it can be an internal one, suchas ferrocene, which has a known oxidation potential.

Although this is a solution process, in contrast to the solid stateOLED, and the reference may be hard to adjust to give values relative tovacuum, the method is good for giving relative numbers. One usefulparameter that may come from the electrochemical measurement is thecarrier gap. If both the reduction and oxidation are reversible, one candetermine the energy difference between the hole and the electron. Thisvalue is important to determine the LUMO energy from a well defined HOMOenergy.

The preferred method to estimate HOMO energies in the solid state isUPS. This is a photoelectric measurement, where the solid is irradiatedwith UV photons. The energy of the photons is gradually increased untilphoto-generated electrons are evolved. The onset of ejected electronsgives the energy of the HOMO. The best accepted method for determiningHOMO energies is UPS, which gives values in eV relative to vacuum. Thisis the binding energy for the electron.

A first energy level (HOMO or LUMO) is considered “less than” or “lower”than a second energy level if it is lower on a conventional energy leveldiagram, which means that the first energy level would have a value thatis more negative than the second energy level.

Examples of such groups -L¹-X¹ and -L²-X² are

wherein

X³ represents O, S or N—R^(121′), especially N—R^(121′),

X⁹ represents O, S or N—R^(121′), especially O,

Q¹ and Q² represents atoms necessary for forming a carbocyclic aromatic,or heterocyclic aromatic ring, which can optionally be condensed withother ring(s) to form a condensed ring, and/or can optionally besubstituted by G,

R¹¹⁶ and R¹¹⁷ are as defined above,

R^(121′) is H; C₆-C₁₈aryl; or C₂-C₂₀heteroaryl; which can optionally besubstituted by C₁-C₁₈alkyl, C₁-C₁₈perfluoroalkyl, or C₁-C₁₈alkoxy;C₁-C₁₈alkyl; or C₁-C₁₈alkyl which is interrupted by —O—;

R^(120′), R¹²³, R¹²⁴ and R¹²⁵ are independently of each other H,C₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by E and/or interrupted byD, C₁-C₁₈perfluoroalkyl, C₆-C₂₄aryl, which can optionally be substitutedby G, C₂-C₂₀heteroaryl, which can optionally be substituted by G,C₂-C₁₈alkenyl, C₂-C₁₈alkynyl, C₁-C₁₈alkoxy, C₁-C₁₈alkoxy which issubstituted by E and/or interrupted by D, or C₇-C₂₅aralkyl,

R¹²⁸ and R^(128′) are independently of each other H, CN , C₁-C₁₈alkyl,C₁-C₁₈alkyl which is substituted by E and/or interrupted by D,C₁-C₁₈perfluoroalkyl, C₆-C₂₄aryl, which can optionally be substituted byG, C₂-C₂₀heteroaryl, which can optionally be substituted by G,C₂-C₁₈alkenyl, C₂-C₁₈alkynyl, C₁-C₁₈alkoxy, C₁-C₁₈alkoxy which issubstituted by E and/or interrupted by D, or C₇-C₂₅aralkyl,

L¹ is a single bond, —(CR⁴⁷═CR⁴⁸)_(m2)—, —(Ar³)_(m3)—,—[Ar³(Y¹)_(m5)]_(m4)—, —[(Y¹)_(m5)Ar³]_(m4)—,

or —[Ar³(Y²)_(m5)Ar⁴]_(m4)—, wherein

Y¹ is —(CR⁴⁷═CR⁴⁸)—,

Y² is NR⁴⁹, O, S, C═O, C(═O)O, wherein R⁴⁹ is C₆-C₁₈aryl which canoptionally be substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; C₁-C₁₈alkyl;or C₁-C₁₈alkyl which is interrupted by —O—;

R⁴⁷ and R⁴⁸ are independently of each other hydrogen, C₁-C₂₀alkyl, orC₆-C₂₄aryl, which can optionally be substituted by G,

m5 is an integer of 1 to 10, m2 is an integer of 1 to 10, m3 is aninteger of 1 to 5, m4 is an integer of 1 to 5,

Ar³ and Ar⁴ are independently of each other arylen, or heteroarylen,which can optionally be substituted.

X⁴, X⁵ and X⁶ are independently of each other N, or CH, with the provisothat at least one, preferably at least two of the substituents X⁴, X⁵and X⁶ are N, and

Ar¹ and Ar² are independently of each other C₆-C₂₄aryl, which canoptionally be substituted by G, or C₂-C₂₀heteroaryl, which canoptionally be substituted by G, wherein D, E and G are as defined above.

R¹²⁸ and R^(128′) are preferably independently of each other H, CN,C₁-C₁₀alkyl, C₁-C₁₀alkyl which is substituted by E and/or interrupted byD, C₁-C₁₈perfluoroalkyl, C₆-C₂₄aryl, which can optionally be substitutedby G, C₂-C₂₀heteroaryl, which can optionally be substituted by G, orC₇-C₂₅aralkyl.

R^(120′), R¹²³, R¹²⁴ and R¹²⁵ are preferably independently of each otherH, C₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by E and/or interruptedby D, C₁-C₁₈perfluoroalkyl, C₆-C₂₄aryl, which can optionally besubstituted by G, or C₂-C₂₀heteroaryl, which can optionally besubstituted by G,

Specific examples of the aromatic heterocyclic ring formed by Q¹, or Q²include pyridine, pyrazine, pyrimidine, pyridazine and triazine.Preferred are pyridine, pyrazine, pyrimidine and pyridazine, withpyridine and pyrazine being more preferred, and pyridine being stillmore preferred. The (6-membered) aromatic heterocyclic ring formed byQ¹, or Q² may be condensed with other ring(s) to form a condensed ring,or may have a substituent G.

In this aspect of the present invention, more specific examples of thegroups -L¹-X¹ and -L¹-X² are the following groups:

wherein m6 is 0, or an integer 1 to 3,

m7 is 0, 1, or 2,

R¹¹⁶ and R¹¹⁷ are as defined above,

R¹²³, Ar¹ and Ar² are independently of each other phenyl or 1- or2-naphthyl which can be substituted one to three times with C₁-C₁₈alkyl,C₁-C₁₈alkyl, which can optionally be interrupted by O; or C₁-C₁₈alkoxy,which can optionally be interrupted by O,

R¹²⁹ can be the same or different at each occurrence and is F, —CN,C₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by E and/or interrupted byD, C₆-C₂₄aryl, C₆-C₂₄aryl which is substituted by G, C₂-C₂₀heteroaryl,C₂-C₂₀heteroaryl which is substituted by G, C₂-C₁₈alkenyl,C₂-C₁₈alkynyl, C₁-C₁₈alkoxy, C₁-C₁₈alkoxy which is substituted by Eand/or interrupted by D, C₇-C₂₅aralkyl, —C(═O)—R¹³⁰, —C(═O)OR^(130′), or—C(═O)NR¹³¹R^(131′), or substituents R¹²⁹, which are adjacent to eachother, can form a ring,

R¹³¹ and R^(131′) are independently of each other H; C₆-C₁₈aryl; orC₂-C₂₀heteroaryl; which can optionally be substituted by C₁-C₁₈alkyl,C₁-C₁₈perfluoroalkyl, or C₁-C₁₈alkoxy; C₁-C₁₈alkyl; or C₁-C₁₈alkyl whichis interrupted by —O—;

R¹³⁰ and R^(130′) are independently of each other H; C₆-C₁₈aryl;C₆-C₁₈aryl which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy;C₁-C₁₈alkyl; or C₁-C₁₈alkyl which is interrupted by —O—,

X⁷ and X⁸ are independently of each other N, or CR^(127″), whereinR^(127″) has the meaning of R¹²⁶, and R^(120′), R¹²⁴, R¹²⁵, X³, X⁴, X⁵,X⁶, X⁹ and L¹ are as defined above.

Among the above groups -L¹-X¹ and -L¹-X² the following groups are evenmore preferred:

wherein the following groups are most preferred:

L¹ is preferably a single bond, or a group

wherein R⁴¹ can be the same or different at each occurrence and is F,CN, N(R⁴⁵)₂, a C₁-C₂₅alkyl group, a C₄-C₁₈cycloalkyl group, aC₁-C₂₅alkoxy group, in which one or more carbon atoms which are not inneighbourhood to each other could be replaced by —NR⁴⁵—, —O—, —S—,—C(═O)—O—, or —O—C(═O)—O—, and/or wherein one or more hydrogen atoms canbe replaced by F, a C₆-C₂₄aryl group, or a C₆-C₂₄aryloxy group, whereinone or more carbon atoms can be replaced by O, S, or N, and/or which canbe substituted by one or more non-aromatic groups R⁴¹, or two or moregroups R⁴¹ form a ring system;

R⁴⁵ is a C₁-C₂₅alkyl group, a C₄-C₁₈cycloalkyl group, in which one ormore carbon atoms which are not in neighbourhood to each other could bereplaced by —NR^(45″)—, —O—, —S—, —C(═O)—O—, or, —O—C(═O)—O—, and/orwherein one or more hydrogen atoms can be replaced by F, a C₆-C₂₄arylgroup, or a C₆-C₂₄aryloxy group, wherein one or more carbon atoms can bereplaced by O, S, or N, and/or which can be substituted by one or morenon-aromatic groups R⁴¹, and R^(45″) is a C₁-C₂₅alkyl group, or aC₄-C₁₈cycloalkyl group,

n1 is 0, or an integer 1 to 3, and R⁴⁷, R⁴⁸, R¹¹⁹ and R¹²⁰ are asdefined above. Most preferred for L¹ are a single bond, or a group

In a particularly preferred embodiment of the present invention -L¹-X¹and -L²-X² are independently of each other a group

In another preferred embodiment of the present invention -L¹-X¹ and-L²-X² are independently of each other a group

wherein

R¹¹⁶, R^(116′), R¹¹⁷ and R^(117′) are independently of each other H,halogen, —CN, C₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by E and/orinterrupted by D, C₆-C₂₄aryl, C₆-C₂₄aryl which is substituted by G,C₂-C₂₀heteroaryl, C₂-C₂₀heteroaryl which is substituted by G,C₂-C₁₈alkenyl, C₂-C₁₈alkynyl, C₁-C₁₈alkoxy, C₁-C₁₈alkoxy which issubstituted by E and/or interrupted by D, C₇-C₂₅aralkyl,—C(═O)—R^(127′), —C(═O)OR^(127′), or —C(═O)NR^(127′)R^(126′), orsubstituents R¹¹⁶, R^(116′), R¹¹⁷ and R^(117′), which are adjacent toeach other, can form a ring,

R^(126′) and R^(127′) are independently of each other H; C₆-C₁₈aryl;C₆-C₁₈aryl which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy;C₁-C₁₈alkyl; or C₁-C₁₈alkyl which is interrupted by —O—, D, E and G areas defined above.

Preferably, R¹¹⁶, R^(116′), R¹¹⁷ and R^(117′) are independently of eachother H, F, —CN, C₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by Eand/or interrupted by D, C₁-C₁₈alkoxy, C₁-C₁₈alkoxy, which issubstituted by E and/or interrupted by D, C₆-C₂₄aryl, C₆-C₂₄aryl whichis substituted by G,

D is —O—; —NR⁶⁵—; and

E is —OR⁶⁹; —NR⁶⁵R⁶⁶; —CN; or F;

G is E, C₁-C₁₈alkyl, C₁-C₁₈alkyl which is interrupted by O,C₁-C₁₈alkoxy, or C₁-C₁₈alkoxy which interrupted by O, wherein

R⁶⁵ and R⁶⁶ are independently of each other C₆-C₁₈aryl; C₆-C₁₈aryl whichis substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; C₁-C₁₈alkyl; orC₁-C₁₈alkyl which is interrupted by —O—; or

R⁶⁵ and R⁶⁶ together form a five or six membered ring, and

R⁶⁹ is C₆-C₁₈aryl; C₆-C₁₈aryl, which is substituted by C₁-C₁₈alkyl, orC₁-C₁₈alkoxy; C₁-C₁₈alkyl; or C₁-C₁₈alkyl which is interrupted by —O—.

Examples of particularly preferred compounds are compounds A1-A21,B1-B21, C1-C21, and D1-D21, which are shown in claim 7.

The compounds of the formula I, wherein -L¹-X¹ and -L²-X² areindependently of each other —NA¹A^(1′),

can, for example, be prepared according to a process, which comprisesreacting a compound of formula

wherein X¹⁰ stands for halogen, such as bromo or iodo, with a compoundof formula HNA¹A^(1′),

in the presence of a base, such as sodium hydride, potassium carbonate,or sodium carbonate, and a catalyst, such as copper (0) or copper (I)(such as copper, copper-bronze, copper bromide iodide, or copperbromide), in a solvent, such as toluene, dimethyl formamide, or dimethylsulfoxide, wherein A¹, A^(1′), L¹, L², R¹, R², R³, R⁴, R⁵, R⁶, R⁴¹, m1and m are as defined above.

This reaction, referred to as an Ullmann condensation, is described byYamamoto & Kurata, Chem. and Industry, 737-738 (1981), J. Mater. Chem.14 (2004) 2516, H. B. Goodbrand et al., J. Org. Chem. 64 (1999) 670 andk. D. Belfield et al., J. Org. Chem. 65 (2000) 4475 using copper ascatalyst. Additionally palladium catalysts can be used for the couplingof aryl halogen compounds with amines, as described in M. D. Charles etal., Organic Lett. 7 (2005) 3965, A. F. Littke et. al., Angew. Chem.Int. Ed. 41 (2002) 4176 and literature cited therein.

The compounds of formula XX are known from WO08/012250, or can beprepared according, or in analogy to the methods described therein.

The compounds, wherein X¹ and X² are a group

can be prepared according to P. A. Vecchi et al., Org. Lett. 8 (2006)4211-4214.

The compounds, wherein X¹ and X² are a group

can be prepared according to example IV of US2005/0175857.

Halogen is fluorine, chlorine, bromine and iodine.

C₁-C₂₅alkyl is typically linear or branched, where possible. Examplesare methyl, ethyl, n-propyl, isopropyl, n-butyl, sec.-butyl, isobutyl,tert.-butyl, n-pentyl, 2-pentyl, 3-pentyl, 2,2-dimethylpropyl,1,1,3,3-tetramethylpentyl, n-hexyl, 1-methylhexyl,1,1,3,3,5,5-hexamethylhexyl, n-heptyl, isoheptyl,1,1,3,3-tetramethylbutyl, 1-methylheptyl, 3-methylheptyl, n-octyl,1,1,3,3-tetramethylbutyl and 2-ethylhexyl, n-nonyl, decyl, undecyl,dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl,octadecyl, eicosyl, heneicosyl, docosyl, tetracosyl or pentacosyl.C₁-C₈alkyl is typically methyl, ethyl, n-propyl, isopropyl, n-butyl,sec.-butyl, isobutyl, tert.-butyl, n-pentyl, 2-pentyl, 3-pentyl,2,2-dimethyl-propyl, n-hexyl, n-heptyl, n-octyl,1,1,3,3-tetramethylbutyl and 2-ethylhexyl. C₁-C₄alkyl is typicallymethyl, ethyl, n-propyl, isopropyl, n-butyl, sec.-butyl, isobutyl,tert.-butyl.

C₁-C₂₅alkoxy groups are straight-chain or branched alkoxy groups, e.g.methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy,tert-butoxy, amyloxy, isoamyloxy or tert-amyloxy, heptyloxy, octyloxy,isooctyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, tetradecyloxy,pentadecyloxy, hexadecyloxy, heptadecyloxy and octadecyloxy. Examples ofC₁-C₈alkoxy are methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy,sec.-butoxy, isobutoxy, tert.-butoxy, n-pentyloxy, 2-pentyloxy,3-pentyloxy, 2,2-dimethylpropoxy, n-hexyloxy, n-heptyloxy, n-octyloxy,1,1,3,3-tetramethylbutoxy and 2-ethylhexyloxy, preferably C₁-C₄alkoxysuch as typically methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy,sec.-butoxy, isobutoxy, tert.-butoxy. The term “alkylthio group” meansthe same groups as the alkoxy groups, except that the oxygen atom of theether linkage is replaced by a sulfur atom.

C₂-C₂₅alkenyl groups are straight-chain or branched alkenyl groups, suchas e.g. vinyl, allyl, methallyl, isopropenyl, 2-butenyl, 3-butenyl,isobutenyl, n-penta-2,4-dienyl, 3-methyl-but-2-enyl, n-oct-2-enyl,n-dodec-2-enyl, isododecenyl, n-dodec-2-enyl or n-octadec-4-enyl.

C₂₋₂₄alkynyl is straight-chain or branched and preferably C₂₋₈alkynyl,which may be unsubstituted or substituted, such as, for example,ethynyl, 1-propyn-3-yl, 1-butyn-4-yl, 1-pentyn-5-yl,2-methyl-3-butyn-2-yl, 1,4-pentadiyn-3-yl, 1,3-pentadiyn-5-yl,1-hexyn-6-yl, cis-3-methyl-2-penten-4-yn-1-yl,trans-3-methyl-2-penten-4-yn-1-yl, 1,3-hexadiyn-5-yl, 1-octyn-8-yl,1-nonyn-9-yl, 1-decyn-10-yl, or 1-tetracosyn-24-yl.

C₁-C₁₈perfluoroalkyl, especially C₁-C₄perfluoroalkyl, is a branched orunbranched radical such as for example —CF₃, —CF₂CF₃, —CF₂CF₂CF₃,—CF(CF₃)₂, —(CF₂)₃CF₃, and —C(CF₃)₃.

The terms “haloalkyl, haloalkenyl and haloalkynyl” mean groups given bypartially or wholly substituting the above-mentioned alkyl group,alkenyl group and alkynyl group with halogen, such as trifluoromethyletc. The “aldehyde group, ketone group, ester group, carbamoyl group andamino group” include those substituted by an alkyl group, a cycloalkylgroup, an aryl group, an aralkyl group or a heterocyclic group, whereinthe alkyl group, the cycloalkyl group, the aryl group, the aralkyl groupand the heterocyclic group may be unsubstituted or substituted. The term“silyl group” means a group of formula —SiR^(62′)R^(63′)R^(64′), whereinR^(62′), R^(63′) and R^(64′) are independently of each other aC₁-C₈alkyl group, in particular a C₁-C₄alkyl group, a C₆-C₂₄aryl groupor a C₇-C₁₂aralkyl group, such as a trimethylsilyl group. The term“siloxanyl group” means a group of formula —O—SiR^(62′)R^(63′)R^(64′),wherein R^(62′), R^(63′) and R^(64′) are as defined above, such as atrimethylsiloxanyl group.

The term “cycloalkyl group” is typically C₅-C₁₂cycloalkyl, such ascyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl,cyclodecyl, cycloundecyl, cyclododecyl, preferably cyclopentyl,cyclohexyl, cycloheptyl, or cyclooctyl, which may be unsubstituted orsubstituted. The term “cycloalkenyl group” means an unsaturatedalicyclic hydrocarbon group containing one or more double bonds, such ascyclopentenyl, cyclopentadienyl, cyclohexenyl and the like, which may beunsubstituted or substituted. The cycloalkyl group, in particular acyclohexyl group, can be condensed one or two times by phenyl which canbe substituted one to three times with C₁-C₄-alkyl, halogen and cyano.Examples of such condensed cyclohexyl groups are:

in particular

wherein R⁵¹, R⁵², R⁵³, R⁵⁴, R⁵⁵ and R⁵⁶ are independently of each otherC₁-C₈-alkyl, C₁-C₈-alkoxy, halogen and cyano, in particular hydrogen.

Aryl is usually C₆-C₃₀aryl, preferably C₆-C₂₄aryl, which optionally canbe substituted, such as, for example, phenyl, 4-methylphenyl,4-methoxyphenyl, naphthyl, especially 1-naphthyl, or 2-naphthyl,biphenylyl, terphenylyl, pyrenyl, 2- or 9-fluorenyl, phenanthryl,anthryl, tetracyl, pentacyl, hexacyl, or quaderphenylyl, which may beunsubstituted or substituted.

The term “aralkyl group” is typically C₇-C₂₄aralkyl, such as benzyl,2-benzyl-2-propyl, β-phenyl-ethyl, α,α-dimethylbenzyl, ω-phenyl-butyl,ω,ω-dimethyl-ω-phenyl-butyl, ω-phenyl-dodecyl, ω-phenyl-octadecyl,ω-phenyl-eicosyl or ω-phenyl-docosyl, preferably C₇-C₁₈aralkyl such asbenzyl, 2-benzyl-2-propyl, β-phenyl-ethyl, α,α-dimethylbenzyl,ω-phenyl-butyl, ω,ω-dimethyl-ω-phenyl-butyl, ω-phenyl-dodecyl orω-phenyl-octadecyl, and particularly preferred C₇-C₁₂aralkyl such asbenzyl, 2-benzyl-2-propyl, β-phenyl-ethyl, α,α-dimethylbenzyl,ω-phenyl-butyl, or ω,ω-dimethyl-ω-phenyl-butyl, in which both thealiphatic hydrocarbon group and aromatic hydrocarbon group may beunsubstituted or substituted.

The term “aryl ether group” is typically a C₆₋₂₄aryloxy group, that isto say O—C₆₋₂₄aryl, such as, for example, phenoxy or 4-methoxyphenyl.The term “aryl thioether group” is typically a C₆₋₂₄arylthio group, thatis to say S—C₆₋₂₄aryl, such as, for example, phenylthio or4-methoxyphenylthio. The term “carbamoyl group” is typically aC₁₋₁₈carbamoyl radical, preferably C₁₋₈carbamoyl radical, which may beunsubstituted or substituted, such as, for example, carbamoyl,methylcarbamoyl, ethylcarbamoyl, n-butylcarbamoyl, tert-butylcarbamoyl,dimethylcarbamoyloxy, morpholinocarbamoyl or pyrrolidinocarbamoyl.

The terms “aryl” and “alkyl” in alkylamino groups, dialkylamino groups,alkylarylamino groups, arylamino groups and diaryl groups are typicallyC₁-C₂₅alkyl and C₆-C₂₄aryl, respectively.

Alkylaryl refers to alkyl-substituted aryl radicals, especiallyC₇-C₁₂alkylaryl. Examples are tolyl, such as 3-methyl-, or4-methylphenyl, or xylyl, such as 3,4-dimethylphenyl, or3,5-dimethylphenyl.

Heteroaryl is typically C₂-C₂₆heteroaryl, i.e. a ring with five to sevenring atoms or a condensed ring system, wherein nitrogen, oxygen orsulfur are the possible hetero atoms, and is typically an unsaturatedheterocyclic group with five to 30 atoms having at least six conjugatedπ-electrons such as thienyl, benzo[b]thienyl, dibenzo[b,d]thienyl,thianthrenyl, furyl, furfuryl, 2H-pyranyl, benzofuranyl,isobenzofuranyl, dibenzofuranyl, phenoxythienyl, pyrrolyl, imidazolyl,pyrazolyl, pyridyl, bipyridyl, triazinyl, pyrimidinyl, pyrazinyl,pyridazinyl, indolizinyl, isoindolyl, indolyl, indazolyl, purinyl,quinolizinyl, chinolyl, isochinolyl, phthalazinyl, naphthyridinyl,chinoxalinyl, chinazolinyl, cinnolinyl, pteridinyl, carbazolyl,carbolinyl, benzotriazolyl, benzoxazolyl, phenanthridinyl, acridinyl,pyrimidinyl, phenanthrolinyl, phenazinyl, isothiazolyl, phenothiazinyl,isoxazolyl, furazanyl or phenoxazinyl, which can be unsubstituted orsubstituted.

Examples of a five or six membered ring formed by, for example, R⁶⁵ andR⁶⁶, respectively are heterocycloalkanes or heterocycloalkenes havingfrom 3 to 5 carbon atoms which can have one additional hetero atomselected from nitrogen, oxygen and sulfur, for example

which can be part of a bicyclic system, for example

Possible substituents of the above-mentioned groups are C₁-C₈alkyl, ahydroxyl group, a mercapto group, C₁-C₈alkoxy, C₁-C₈alkylthio, halogen,halo-C₁-C₈alkyl, a cyano group, an aldehyde group, a ketone group, acarboxyl group, an ester group, a carbamoyl group, an amino group, anitro group or a silyl group, wherein C₁-C₈alkyl, C₁-C₈alkoxy, a cyanogroup, or a silyl group are preferred.

If a substituent, such as, for example R⁶ occurs more than one time in agroup, it can be different in each occurrence.

The wording “substituted by G” means that one, or more, especially oneto three substituents G might be present.

As described above, the aforementioned groups may be substituted by Eand/or, if desired, interrupted by D. Interruptions are of coursepossible only in the case of groups containing at least 2 carbon atomsconnected to one another by single bonds; C₆-C₁₈aryl is not interrupted;interrupted arylalkyl or alkylaryl contains the unit D in the alkylmoiety. C₁-C₁₈alkyl substituted by one or more E and/or interrupted byone or more units D is, for example, (CH₂CH₂O)₁₋₉—R^(x), where R^(x) isH or C₁-C₁₀alkyl or C₂-C₁₀alkanoyl (e.g. CO—CH(C₂H₅)C₄H₉),CH₂—CH(OR^(y)′)—CH₂—O—R^(y), where R^(y) is C₁-C₁₈alkyl,C₅-C₁₂cycloalkyl, phenyl, C₇-C₁₅phenylalkyl, and R^(y)′ embraces thesame definitions as R^(y) or is H;

C₁-C₈alkylene-COO—R^(z), e.g. CH₂COOR_(z,) CH(CH₃)COOR^(z),C(CH₃)₂COOR^(z), where R^(z) is H, C₁-C₁₈alkyl, (CH₂CH₂O)₁₋₉—R^(x), andR^(x) embraces the definitions indicated above; CH₂CH₂—O—CO—CH═CH₂;CH₂CH(OH)CH₂—O—CO—C(CH₃)═CH₂.

Preferred arylene radicals are 1,4-phenylene, 2,5-tolylene,1,4-naphthylene, 1,9-antracylene, 2,7-phenantrylene and2,7-dihydrophenantrylene.

Preferred heteroarylene radicals are 2,5-pyrazinylene,3,6-pyridazinylene, 2,5-pyridinylene, 2,5-pyrimidinylene,1,3,4-thiadiazol-2,5-ylene, 1,3-thiazol-2,4-ylene,1,3-thiazol-2,5-ylene, 2,4-thiophenylene, 2,5-thiophenylene,1,3-oxazol-2,4-ylene, 1,3-oxazol-2,5-ylene and1,3,4-oxadiazol-2,5-ylene, 2,5-indenylene and 2,6-indenylene.

The electronic device of the present invention is preferably anelectroluminescent (EL) device. The compounds of formula I can be usedin organic light emitting diodes (OLEDs) as hosts for phosphorescentcompounds. Accordingly, the present invention also relates to anelectroluminescent device, comprising a compound of formula I. In apreferred embodiment the electroluminescent device comprising a cathode,an anode, and therebetween a light emitting layer containing a hostmaterial and a phosphorescent light-emitting material wherein the hostmaterial is a compound of formula I.

Suitably, the light-emitting layer of the OLED device comprises a hostmaterial and one or more guest materials for emitting light. At leastone of the host materials is a compound comprising a compound of formulaI. The light-emitting guest material(s) is usually present in an amountless than the amount of host materials and is typically present in anamount of up to 15 wt % of the host, more typically from 0.1 to 10 wt %of the host, and commonly from 2 to 8% of the host. For convenience, thephosphorescent complex guest material may be referred to herein as aphosphorescent material. The emissive layer may comprise a singlematerial, that combines transport and emissive properties. Whether theemissive material is a dopant or a major constituent, emissive layer maycomprise other materials, such as dopants that tune the emission of theemissive layer. The emissive layer may include a plurality of emissivematerials capable of, in combination, emitting a desired spectrum oflight.

Other Host Materials for Phosphorescent Materials

The host material useful in the invention may be used alone or incombination with other host materials. Other host materials should beselected so that the triplet exciton can be transferred efficiently fromthe host material to the phosphorescent material. Suitable hostmaterials are described in WO00/70655; 01/39234; 01/93642; 02/074015;02/15645, and US20020117662. Suitable hosts include certain aryl amines,triazoles, indoles and carbazole compounds. Examples of hosts are4,4′-N,N′-dicarbazole-biphenyl (CBP),2,2′-dimethyl-4,4′-N,N′-dicarbazole-biphenyl,m-(N,N′-dicarbazole)benzene, and poly(N-vinylcarbazole), including theirderivatives.

Desirable host materials are capable of forming a continuous film. Thelight-emitting layer may contain more than one host material in order toimprove the device's film morphology, electrical properties, lightemission efficiency, and lifetime. The light emitting layer may containa first host material that has good hole-transporting properties, and asecond host material that has good electron-transporting properties.

Phosphorescent Materials

Phosphorescent materials may be used alone or, in certain cases, incombination with each other, either in the same or different layers.Examples of phosphorescent and related materials are described inWO00/57676, WO00/70655, WO01/41512, WO02/15645, US2003/0017361,WO01/93642, WO01/39234, U.S. Pat. No. 6,458,475, WO02/071813, U.S. Pat.No. 6,573,651, US2002/0197511, WO02/074015, U.S. Pat. No. 6,451,455,US2003/0072964, US2003/0068528, U.S. Pat. Nos. 6,413,656, 6,515,298,6,451,415, 6,097,147, US2003/0124381, US2003/0059646, US2003/0054198,EP1239526, EP1238981, EP1244155, US2002/0100906, US2003/0068526,US2003/0068535, JP2003073387, JP2003073388, US2003/0141809,US2003/0040627, JP2003059667, JP2003073665 and US2002/0121638.

The emission wavelengths of cyclometallated Ir(III) complexes of thetype IrL₃ and IrL₂L′, such as the green-emittingfac-tris(2-phenylpyridinato-N,C^(2′))iridium(III) andbis(2-phenylpyridinato-N,C^(2′))Iridium(III) (acetylacetonate) may beshifted by substitution of electron donating or withdrawing groups atappropriate positions on the cyclometallating ligand L, or by choice ofdifferent heterocycles for the cyclometallating ligand L. The emissionwavelengths may also be shifted by choice of the ancillary ligand L′.Examples of red emitters are bis(1-(phenyl)isoquinoline)iridium (III)acetylanetonate,(acetylanetonato)bis-(2,3,5-triphenylpyrazinato)iridium(III),bis(2-(2′-benzothienyl)pyridinato-N,C^(3′))iridium(III)-(acetylacetonate)and tris(1-phenylisoquinolinato-N,C)iridium(III). A blue-emittingexample isbis(2-(4,6-diflourophenyl)-pyridinato-N,C^(2′))Iridium(III)(picolinate).

Red electrophosphorescence has been reported, usingbis(2-(2′-benzo[4,5-a]thienyl)pyridinato-N,C³)iridium(acetylacetonate)[Btp₂Ir(acac)]as the phosphorescent material (Adachi, C., Lamansky, S., Baldo, M. A.,Kwong, R. C., Thompson, M. E., and Forrest, S. R., App. Phys. Lett., 78,1622 1624 (2001)).

Other important phosphorescent materials include cyclometallated Pt(II)complexes such as cis-bis(2-phenylpyridinato-N,C^(2′))platinum(II),cis-bis(2-(2′-thienyl)pyridinato-N,C^(3′))platinum(II),cis-bis(2-(2′-thienyl)quinolinato-N,C^(5′))platinum(II), or(2-(4,6-diflourophenyl)pyridinato-NC2′) platinum(II)acetylacetonate.Pt(II)porphyrin complexes such as2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine platinum(H) are alsouseful phosphorescent materials.

Still other examples of useful phosphorescent materials includecoordination complexes of the trivalent lanthanides such as Th³⁺ andEu³⁺ (J. Kido et al, Appl. Phys. Lett., 65, 2124 (1994)).

Other important phosphorescent materials are described in WO06/000544and PCT/EP2008/051702.

Examples of phosphorescent materials are compounds A-1 to B-234, B-1 toB-234, C-1 to C-44 and D-1 to D-234, which are described inPCT/EP2008/051702:

Cpd. R² R³ R⁶ A-1 H H H A-2 H H OCH₃ A-3 H H OCH₂CH₃ A-4 H H O-n-butylA-5 H H O-iso-butyl A-6 H H O-2-butyl A-7 H H O-2-ethylhexyl A-8 H HN(CH₃)₂ A-9 H H NPh₂ A-10 H CF₃ H A-11 CF₃ H H A-12 H CF₃ OCH₃ A-13 CF₃H OCH₃ A-14 H CF₃ OCH₂CH₃ A-15 CF₃ H OCH₂CH₃ A-16 H CF₃ O-n-butyl A-17CF₃ H O-n-butyl A-18 H CF₃ O-iso-butyl A-19 CF₃ H O-iso-butyl A-20 H CF₃O-2-butyl A-21 CF₃ H O-2-butyl A-22 H CF₃ O-2-ethylhexyl A-23 CF₃ HO-2-ethylhexyl A-24 H CF₃ N(CH₃)₂ A-25 CF₃ H N(CH₃)₂ A-26 H CF₃ NPh₂A-27 CF₃ H NPh₂ A-28 H CN H A-29 CN H H A-30 H CN OCH₃ A-31 CN H OCH₂CH₃A-32 H CN OCH₂CH₃ A-33 CN H O-n-butyl A-34 H CN O-n-butyl A-35 CN HO-iso-butyl A-36 H CN O-iso-butyl A-37 CN H O-2-butyl A-38 H CNO-2-butyl A-39 CN H O-2-ethylhexyl A-40 H CN O-2-ethylhexyl A-41 CN HN(CH₃)₂ A-42 H CN N(CH₃)₂ A-43 CN H NPh₂ A-44 H CN NPh₂

Cpd. L′ R² R³ R⁶ B-1 A¹⁾ H H H B-2 A¹⁾ H H OCH₃ B-3 A¹⁾ H H OCH₂CH₃ B-4A¹⁾ H H O-n-butyl B-5 A¹⁾ H H O-iso-butyl B-6 A¹⁾ H H O-2-butyl B-7 A¹⁾H H O-2-ethylhexyl B-8 A¹⁾ H H N(CH₃)₂ B-9 A¹⁾ H H NPh₂ B-10 A¹⁾ H CF₃ HB-11 A¹⁾ CF₃ H H B-12 A¹⁾ H CF₃ OCH₃ B-13 A¹⁾ CF₃ H OCH₃ B-14 A¹⁾ H CF₃OCH₂CH₃ B-15 A¹⁾ CF₃ H OCH₂CH₃ B-16 A¹⁾ H CF₃ O-n-butyl B-17 A¹⁾ CF₃ HO-n-butyl B-18 A¹⁾ H CF₃ O-iso-butyl B-19 A¹⁾ CF₃ H O-iso-butyl B-20 A¹⁾H CF₃ O-2-butyl B-21 A¹⁾ CF₃ H O-2-butyl B-22 A¹⁾ H CF₃ O-2-ethylhexylB-23 A¹⁾ CF₃ H O-2-ethylhexyl B-24 A¹⁾ H CF₃ N(CH₃)₂ B-25 A¹⁾ CF₃ HN(CH₃)₂ B-26 A¹⁾ H CF₃ NPh₂ B-27 A¹⁾ CF₃ H NPh₂ B-28 A¹⁾ H CN H B-29 A¹⁾CN H H B-30 A¹⁾ CN H OCH₃ B-31 A¹⁾ H CN OCH₃ B-32 A¹⁾ CN H OCH₂CH₃ B-33A¹⁾ H CN OCH₂CH₃ B-34 A¹⁾ CN H O-n-butyl B-35 A¹⁾ H CN O-n-butyl B-36A¹⁾ CN H O-iso-butyl B-37 A¹⁾ H CN O-iso-butyl B-38 A¹⁾ CN H O-2-butylB-39 A¹⁾ H CN O-2-butyl B-40 A¹⁾ CN H O-2-ethylhexyl B-41 A¹⁾ H CNO-2-ethylhexyl B-42 A¹⁾ CN H N(CH₃)₂ B-43 A¹⁾ H CN N(CH₃)₂ B-44 A¹⁾ CN HNPh₂ B-45 A¹⁾ H CN NPh₂ B-46 B¹⁾ H H H B-47 B¹⁾ H H OCH₃ B-48 B¹⁾ H HOCH₂CH₃ B-49 B¹⁾ H H O-n-butyl B-50 B¹⁾ H H O-iso-butyl B-51 B¹⁾ H HO-2-butyl B-52 B¹⁾ H H O-2-ethylhexyl B-53 B¹⁾ H H N(CH₃)₂ B-54 B¹⁾ H HNPh₂ B-55 B¹⁾ H CF₃ H B-56 B¹⁾ CF₃ H H B-57 B¹⁾ H CF₃ OCH₃ B-58 B¹⁾ CF₃H OCH₃ B-59 B¹⁾ H CF₃ OCH₂CH₃ B-60 B¹⁾ CF₃ H OCH₂CH₃ B-61 B¹⁾ H CF₃O-n-butyl B-62 B¹⁾ CF₃ H O-n-butyl B-63 B¹⁾ H CF₃ O-iso-butyl B-64 B¹⁾CF₃ H O-iso-butyl B-65 B¹⁾ H CF₃ O-2-butyl B-66 B¹⁾ CF₃ H O-2-butyl B-67B¹⁾ H CF₃ O-2-ethylhexyl B-68 B¹⁾ CF₃ H O-2-ethylhexyl B-69 B¹⁾ H CF₃N(CH₃)₂ B-70 B¹⁾ CF₃ H N(CH₃)₂ B-71 B¹⁾ H CF₃ NPh₂ B-72 B¹⁾ CF₃ H NPh₂B-73 B¹⁾ H CN H B-74 B¹⁾ CN H H B-75 B¹⁾ CN H OCH₃ B-76 B¹⁾ H CN OCH₃B-77 B¹⁾ CN H OCH₂CH₃ B-78 B¹⁾ H CN OCH₂CH₃ B-79 B¹⁾ CN H O-n-butyl B-80B¹⁾ H CN O-n-butyl B-81 B¹⁾ CN H O-iso-butyl B-82 B¹⁾ H CN O-iso-butylB-83 B¹⁾ CN H O-2-butyl B-84 B¹⁾ H CN O-2-butyl B-85 B¹⁾ CN HO-2-ethylhexyl B-86 B¹⁾ H CN O-2-ethylhexyl B-87 B¹⁾ CN H N(CH₃)₂ B-88B¹⁾ H CN N(CH₃)₂ B-89 B¹⁾ CN H NPh₂ B-99 B¹⁾ H CN NPh₂ B-100 C¹⁾ H H HB-101 C¹⁾ H H OCH₃ B-102 C¹⁾ H H OCH₂CH₃ B-103 C¹⁾ H H O-n-butyl B-104C¹⁾ H H O-iso-butyl B-105 C¹⁾ H H O-2-butyl B-106 C¹⁾ H H O-2-ethylhexylB-107 C¹⁾ H H N(CH₃)₂ B-108 C¹⁾ H H NPh₂ B-109 C¹⁾ H CF₃ H B-110 C¹⁾ CF₃H H B-111 C¹⁾ H CF₃ OCH₃ B-112 C¹⁾ CF₃ H OCH₃ B-113 C¹⁾ H CF₃ OCH₂CH₃B-114 C¹⁾ CF₃ H OCH₂CH₃ B-115 C¹⁾ H CF₃ O-n-butyl B-116 C¹⁾ CF₃ HO-n-butyl B-117 C¹⁾ H CF₃ O-iso-butyl B-118 C¹⁾ CF₃ H O-iso-butyl B-119C¹⁾ H CF₃ O-2-butyl B-120 C¹⁾ CF₃ H O-2-butyl B-121 C¹⁾ H CF₃O-2-ethylhexyl B-122 C¹⁾ CF₃ H O-2-ethylhexyl B-123 C¹⁾ H CF₃ N(CH₃)₂B-124 C¹⁾ CF₃ H N(CH₃)₂ B-125 C¹⁾ H CF₃ NPh₂ B-126 C¹⁾ CF₃ H NPh₂ B-127C¹⁾ H CN H B-128 C¹⁾ CN H H B-129 C¹⁾ CN H OCH₃ B-130 C¹⁾ H CN OCH₃B-131 C¹⁾ CN H OCH₂CH₃ B-132 C¹⁾ H CN OCH₂CH₃ B-133 C¹⁾ CN H O-n-butylB-134 C¹⁾ H CN O-n-butyl B-135 C¹⁾ CN H O-iso-butyl B-136 C¹⁾ H CNO-iso-butyl B-137 C¹⁾ CN H O-2-butyl B-138 C¹⁾ H CN O-2-butyl B-139 C¹⁾CN H O-2-ethylhexyl B-140 C¹⁾ H CN O-2-ethylhexyl B-141 C¹⁾ CN H N(CH₃)₂B-142 C¹⁾ H CN N(CH₃)₂ B-143 C¹⁾ H CN NPh₂ B-144 C¹⁾ CN H NPh₂ B-145 D¹⁾H H H B-146 D¹⁾ H H OCH₃ B-147 D¹⁾ H H OCH₂CH₃ B-148 D¹⁾ H H O-n-butylB-149 D¹⁾ H H O-iso-butyl B-150 D¹⁾ H H O-2-butyl B-151 D¹⁾ H HO-2-ethylhexyl B-152 D¹⁾ H H N(CH₃)₂ B-153 D¹⁾ H H NPh₂ B-154 D¹⁾ H CF₃H B-155 D¹⁾ CF₃ H H B-156 D¹⁾ H CF₃ OCH₃ B-157 D¹⁾ CF₃ H OCH₃ B-158 D¹⁾H CF₃ OCH₂CH₃ B-159 D¹⁾ CF₃ H OCH₂CH₃ B-160 D¹⁾ H CF₃ O-n-butyl B-161D¹⁾ CF₃ H O-n-butyl B-162 D¹⁾ H CF₃ O-iso-butyl B-163 D¹⁾ CF₃ HO-iso-butyl B-164 D¹⁾ H CF₃ O-2-butyl B-165 D¹⁾ CF₃ H O-2-butyl B-166D¹⁾ H CF₃ O-2-ethylhexyl B-167 D¹⁾ CF₃ H O-2-ethylhexyl B-168 D¹⁾ H CF₃N(CH₃)₂ B-169 D¹⁾ CF₃ H N(CH₃)₂ B-170 D¹⁾ H CF₃ NPh₂ B-171 D¹⁾ CF₃ HNPh₂ B-172 D¹⁾ H CN H B-173 D¹⁾ CN H H B-174 D¹⁾ CN H OCH₃ B-175 D¹⁾ HCN OCH₃ B-176 D¹⁾ CN H OCH₂CH₃ B-177 D¹⁾ H CN OCH₂CH₃ B-178 D¹⁾ CN HO-n-butyl B-179 D¹⁾ H CN O-n-butyl B-180 D¹⁾ CN H O-iso-butyl B-181 D¹⁾H CN O-iso-butyl B-182 D¹⁾ CN H O-2-butyl B-183 D¹⁾ H CN O-2-butyl B-184D¹⁾ CN H O-2-ethylhexyl B-185 D¹⁾ H CN O-2-ethylhexyl B-186 D¹⁾ CN HN(CH₃)₂ B-187 D¹⁾ H CN N(CH₃)₂ B-188 D¹⁾ CN H NPh₂ B-189 D¹⁾ H CN NPh₂B-190 E¹⁾ H H H B-191 E¹⁾ H H OCH₃ B-192 E¹⁾ H H OCH₂CH₃ B-193 E¹⁾ H HO-n-butyl B-194 E¹⁾ H H O-iso-butyl B-195 E¹⁾ H H O-2-butyl B-196 E¹⁾ HH O-2-ethylhexyl B-197 E¹⁾ H H N(CH₃)₂ B-198 E¹⁾ H H NPh₂ B-199 E¹⁾ HCF₃ H B-200 E¹⁾ CF₃ H H B-201 E¹⁾ H CF₃ OCH₃ B-202 E¹⁾ CF₃ H OCH₃ B-203E¹⁾ H CF₃ OCH₂CH₃ B-204 E¹⁾ CF₃ H OCH₂CH₃ B-205 E¹⁾ H CF₃ O-n-butylB-206 E¹⁾ CF₃ H O-n-butyl B-207 E¹⁾ H CF₃ O-iso-butyl B-208 E¹⁾ CF₃ HO-iso-butyl B-209 E¹⁾ H CF₃ O-2-butyl B-210 E¹⁾ CF₃ H O-2-butyl B-211E¹⁾ H CF₃ O-2-ethylhexyl B-212 E¹⁾ CF₃ H O-2-ethylhexyl B-213 E¹⁾ H CF₃N(CH₃)₂ B-214 E¹⁾ CF₃ H N(CH₃)₂ B-215 E¹⁾ H CF₃ NPh₂ B-216 E¹⁾ CF₃ HNPh₂ B-217 E¹⁾ H CN H B-218 E¹⁾ CN H H B-219 E¹⁾ CN H OCH₃ B-220 E¹⁾ HCN OCH₃ B-221 E¹⁾ CN H OCH₂CH₃ B-222 E¹⁾ H CN OCH₂CH₃ B-223 E¹⁾ CN HO-n-butyl B-224 E¹⁾ H CN O-n-butyl B-225 E¹⁾ CN H O-iso-butyl B-226 E¹⁾H CN O-iso-butyl B-227 E¹⁾ CN H O-2-butyl B-228 E¹⁾ H CN O-2-butyl B-229E¹⁾ CN H O-2-ethylhexyl B-230 E¹⁾ H CN O-2-ethylhexyl B-231 E¹⁾ CN HN(CH₃)₂ B-232 E¹⁾ H CN N(CH₃)₂ B-233 E¹⁾ CN H NPh₂ B-234 E¹⁾ H CN NPh₂

Cpd. R² R³ R⁶ C-1 H H H C-2 H H OCH₃ C-3 H H OCH₂CH₃ C-4 H H O-n-butylC-5 H H O-iso-butyl C-6 H H O-2-butyl C-7 H H O-2-ethylhexyl C-8 H HN(CH₃)₂ C-9 H H NPh₂ C-10 H CF₃ H C-11 CF₃ H H C-12 H CF₃ OCH₃ C-13 CF₃H OCH₃ C-14 H CF₃ OCH₂CH₃ C-15 CF₃ H OCH₂CH₃ C-16 H CF₃ O-n-butyl C-17CF₃ H O-n-butyl C-18 H CF₃ O-iso-butyl C-19 CF₃ H O-iso-butyl C-20 H CF₃O-2-butyl C-21 CF₃ H O-2-butyl C-22 H CF₃ O-2-ethylhexyl C-23 CF₃ HO-2-ethylhexyl C-24 H CF₃ N(CH₃)₂ C-25 CF₃ H N(CH₃)₂ C-26 H CF₃ NPh₂C-27 CF₃ H NPh₂ C-28 H CN H C-29 CN H H C-30 H CN OCH₃ C-31 CN H OCH₂CH₃C-32 H CN OCH₂CH₃ C-33 CN H O-n-butyl C-34 H CN O-n-butyl C-35 CN HO-iso-butyl C-36 H CN O-iso-butyl C-37 CN H O-2-butyl C-38 H CNO-2-butyl C-39 CN H O-2-ethylhexyl C-40 H CN O-2-ethylhexyl C-41 CN HN(CH₃)₂ C-42 H CN N(CH₃)₂ C-43 CN H NPh₂ C-44 H CN NPh₂

Cpd. L′ R² R³ R⁶ D-1 A¹⁾ H H H D-2 A¹⁾ H H OCH₃ D-3 A¹⁾ H H OCH₂CH₃ D-4A¹⁾ H H O-n-butyl D-5 A¹⁾ H H O-iso-butyl D-6 A¹⁾ H H O-2-butyl D-7 A¹⁾H H O-2-ethylhexyl D-8 A¹⁾ H H N(CH₃)₂ D-9 A¹⁾ H H NPh₂ D-10 A¹⁾ H CF₃ HD-11 A¹⁾ CF₃ H H D-12 A¹⁾ H CF₃ OCH₃ D-13 A¹⁾ CF₃ H OCH₃ D-14 A¹⁾ H CF₃OCH₂CH₃ D-15 A¹⁾ CF₃ H OCH₂CH₃ D-16 A¹⁾ H CF₃ O-n-butyl D-17 A¹⁾ CF₃ HO-n-butyl D-18 A¹⁾ H CF₃ O-iso-butyl D-19 A¹⁾ CF₃ H O-iso-butyl D-20 A¹⁾H CF₃ O-2-butyl D-21 A¹⁾ CF₃ H O-2-butyl D-22 A¹⁾ H CF₃ O-2-ethylhexylD-23 A¹⁾ CF₃ H O-2-ethylhexyl D-24 A¹⁾ H CF₃ N(CH₃)₂ D-25 A¹⁾ CF₃ HN(CH₃)₂ D-26 A¹⁾ H CF₃ NPh₂ D-27 A¹⁾ CF₃ H NPh₂ D-28 A¹⁾ H CN H D-29 A¹⁾CN H H D-30 A¹⁾ CN H OCH₃ D-31 A¹⁾ H CN OCH₃ D-32 A¹⁾ CN H OCH₂CH₃ D-33A¹⁾ H CN OCH₂CH₃ D-34 A¹⁾ CN H O-n-butyl D-35 A¹⁾ H CN O-n-butyl D-36A¹⁾ CN H O-iso-butyl D-37 A¹⁾ H CN O-iso-butyl D-38 A¹⁾ CN H O-2-butylD-39 A¹⁾ H CN O-2-butyl D-40 A¹⁾ CN H O-2-ethylhexyl D-41 A¹⁾ H CNO-2-ethylhexyl D-42 A¹⁾ CN H N(CH₃)₂ D-43 A¹⁾ H CN N(CH₃)₂ D-44 A¹⁾ CN HNPh₂ D-45 A¹⁾ H CN NPh₂ D-46 B¹⁾ H H H D-47 B¹⁾ H H OCH₃ D-48 B¹⁾ H HOCH₂CH₃ D-49 B¹⁾ H H O-n-butyl D-50 B¹⁾ H H O-iso-butyl D-51 B¹⁾ H HO-2-butyl D-52 B¹⁾ H H O-2-ethylhexyl D-53 B¹⁾ H H N(CH₃)₂ D-54 B¹⁾ H HNPh₂ D-55 B¹⁾ H CF₃ H D-56 B¹⁾ CF₃ H H D-57 B¹⁾ H CF₃ OCH₃ D-58 B¹⁾ CF₃H OCH₃ D-59 B¹⁾ H CF₃ OCH₂CH₃ D-60 B¹⁾ CF₃ H OCH₂CH₃ D-61 B¹⁾ H CF₃O-n-butyl D-62 B¹⁾ CF₃ H O-n-butyl D-63 B¹⁾ H CF₃ O-iso-butyl D-64 B¹⁾CF₃ H O-iso-butyl D-65 B¹⁾ H CF₃ O-2-butyl D-66 B¹⁾ CF₃ H O-2-butyl D-67B¹⁾ H CF₃ O-2-ethylhexyl D-68 B¹⁾ CF₃ H O-2-ethylhexyl D-69 B¹⁾ H CF₃N(CH₃)₂ D-70 B¹⁾ CF₃ H N(CH₃)₂ D-71 B¹⁾ H CF₃ NPh₂ D-72 B¹⁾ CF₃ H NPh₂D-73 B¹⁾ H CN H D-74 B¹⁾ CN H H D-75 B¹⁾ CN H OCH₃ D-76 B¹⁾ H CN OCH₃D-77 B¹⁾ CN H OCH₂CH₃ D-78 B¹⁾ H CN OCH₂CH₃ D-79 B¹⁾ CN H O-n-butyl D-80B¹⁾ H CN O-n-butyl D-81 B¹⁾ CN H O-iso-butyl D-82 B¹⁾ H CN O-iso-butylD-83 B¹⁾ CN H O-2-butyl D-84 B¹⁾ H CN O-2-butyl D-85 B¹⁾ CN HO-2-ethylhexyl D-86 B¹⁾ H CN O-2-ethylhexyl D-87 B¹⁾ CN H N(CH₃)₂ D-88B¹⁾ H CN N(CH₃)₂ D-89 B¹⁾ CN H NPh₂ D-99 B¹⁾ H CN NPh₂ D-100 C¹⁾ H H HD-101 C¹⁾ H H OCH₃ D-102 C¹⁾ H H OCH₂CH₃ D-103 C¹⁾ H H O-n-butyl D-104C¹⁾ H H O-iso-butyl D-105 C¹⁾ H H O-2-butyl D-106 C¹⁾ H H O-2-ethylhexylD-107 C¹⁾ H H N(CH₃)₂ D-108 C¹⁾ H H NPh₂ D-109 C¹⁾ H CF₃ H D-110 C¹⁾ CF₃H H D-111 C¹⁾ H CF₃ OCH₃ D-112 C¹⁾ CF₃ H OCH₃ D-113 C¹⁾ H CF₃ OCH₂CH₃D-114 C¹⁾ CF₃ H OCH₂CH₃ D-115 C¹⁾ H CF₃ O-n-butyl D-116 C¹⁾ CF₃ HO-n-butyl D-117 C¹⁾ H CF₃ O-iso-butyl D-118 C¹⁾ CF₃ H O-iso-butyl D-119C¹⁾ H CF₃ O-2-butyl D-120 C¹⁾ CF₃ H O-2-butyl D-121 C¹⁾ H CF₃O-2-ethylhexyl D-122 C¹⁾ CF₃ H O-2-ethylhexyl D-123 C¹⁾ H CF₃ N(CH₃)₂D-124 C¹⁾ CF₃ H N(CH₃)₂ D-125 C¹⁾ H CF₃ NPh₂ D-126 C¹⁾ CF₃ H NPh₂ D-127C¹⁾ H CN H D-128 C¹⁾ CN H H D-129 C¹⁾ CN H OCH₃ D-130 C¹⁾ H CN OCH₃D-131 C¹⁾ CN H OCH₂CH₃ D-132 C¹⁾ H CN OCH₂CH₃ D-133 C¹⁾ CN H O-n-butylD-134 C¹⁾ H CN O-n-butyl D-135 C¹⁾ CN H O-iso-butyl D-136 C¹⁾ H CNO-iso-butyl D-137 C¹⁾ CN H O-2-butyl D-138 C¹⁾ H CN O-2-butyl D-139 C¹⁾CN H O-2-ethylhexyl D-140 C¹⁾ H CN O-2-ethylhexyl D-141 C¹⁾ CN H N(CH₃)₂D-142 C¹⁾ H CN N(CH₃)₂ D-143 C¹⁾ H CN NPh₂ D-144 C¹⁾ CN H NPh₂ D-145 D¹⁾H H H D-146 D¹⁾ H H OCH₃ D-147 D¹⁾ H H OCH₂CH₃ D-148 D¹⁾ H H O-n-butylD-149 D¹⁾ H H O-iso-butyl D-150 D¹⁾ H H O-2-butyl D-151 D¹⁾ H HO-2-ethylhexyl D-152 D¹⁾ H H N(CH₃)₂ D-153 D¹⁾ H H NPh₂ D-154 D¹⁾ H CF₃H D-155 D¹⁾ CF₃ H H D-156 D¹⁾ H CF₃ OCH₃ D-157 D¹⁾ CF₃ H OCH₃ D-158 D¹⁾H CF₃ OCH₂CH₃ D-159 D¹⁾ CF₃ H OCH₂CH₃ D-160 D¹⁾ H CF₃ O-n-butyl D-161D¹⁾ CF₃ H O-n-butyl D-162 D¹⁾ H CF₃ O-iso-butyl D-163 D¹⁾ CF₃ HO-iso-butyl D-164 D¹⁾ H CF₃ O-2-butyl D-165 D¹⁾ CF₃ H O-2-butyl D-166D¹⁾ H CF₃ O-2-ethylhexyl D-167 D¹⁾ CF₃ H O-2-ethylhexyl D-168 D¹⁾ H CF₃N(CH₃)₂ D-169 D¹⁾ CF₃ H N(CH₃)₂ D-170 D¹⁾ H CF₃ NPh₂ D-171 D¹⁾ CF₃ HNPh₂ D-172 D¹⁾ H CN H D-173 D¹⁾ CN H H D-174 D¹⁾ CN H OCH₃ D-175 D¹⁾ HCN OCH₃ D-176 D¹⁾ CN H OCH₂CH₃ D-177 D¹⁾ H CN OCH₂CH₃ D-178 D¹⁾ CN HO-n-butyl D-179 D¹⁾ H CN O-n-butyl D-180 D¹⁾ CN H O-iso-butyl D-181 D¹⁾H CN O-iso-butyl D-182 D¹⁾ CN H O-2-butyl D-183 D¹⁾ H CN O-2-butyl D-184D¹⁾ CN H O-2-ethylhexyl D-185 D¹⁾ H CN O-2-ethylhexyl D-186 D¹⁾ CN HN(CH₃)₂ D-187 D¹⁾ H CN N(CH₃)₂ D-188 D¹⁾ CN H NPh₂ D-189 D¹⁾ H CN NPh₂D-190 F¹⁾ H H H D-191 F¹⁾ H H OCH₃ D-192 F¹⁾ H H OCH₂CH₃ D-193 F¹⁾ H HO-n-butyl D-194 F¹⁾ H H O-iso-butyl D-195 F¹⁾ H H O-2-butyl D-196 F¹⁾ HH O-2-ethylhexyl D-197 F¹⁾ H H N(CH₃)₂ D-198 F¹⁾ H H NPh₂ D-199 F¹⁾ HCF₃ H D-200 F¹⁾ CF₃ H H D-201 F¹⁾ H CF₃ OCH₃ D-202 F¹⁾ CF₃ H OCH₃ D-203F¹⁾ H CF₃ OCH₂CH₃ D-204 F¹⁾ CF₃ H OCH₂CH₃ D-205 F¹⁾ H CF₃ O-n-butylD-206 F¹⁾ CF₃ H O-n-butyl D-207 F¹⁾ H CF₃ O-iso-butyl D-208 F¹⁾ CF₃ HO-iso-butyl D-209 F¹⁾ H CF₃ O-2-butyl D-210 F¹⁾ CF₃ H O-2-butyl D-211F¹⁾ H CF₃ O-2-ethylhexyl D-212 F¹⁾ CF₃ H O-2-ethylhexyl D-213 F¹⁾ H CF₃N(CH₃)₂ D-214 F¹⁾ CF₃ H N(CH₃)₂ D-215 F¹⁾ H CF₃ NPh₂ D-216 F¹⁾ CF₃ HNPh₂ D-217 F¹⁾ H CN H D-218 F¹⁾ CN H H D-219 F¹⁾ CN H OCH₃ D-220 F¹⁾ HCN OCH₃ D-221 F¹⁾ CN H OCH₂CH₃ D-222 F¹⁾ H CN OCH₂CH₃ D-223 F¹⁾ CN HO-n-butyl D-224 F¹⁾ H CN O-n-butyl D-225 F¹⁾ CN H O-iso-butyl D-226 F¹⁾H CN O-iso-butyl D-227 F¹⁾ CN H O-2-butyl D-228 F¹⁾ H CN O-2-butyl D-229F¹⁾ CN H O-2-ethylhexyl D-230 F¹⁾ H CN O-2-ethylhexyl D-231 F¹⁾ CN HN(CH₃)₂ D-232 F¹⁾ H CN N(CH₃)₂ D-233 F¹⁾ CN H NPh₂ D-234 F¹⁾ H CN NPh₂D-235 E¹⁾ H H H D-236 E¹⁾ H H OCH₃ D-237 E¹⁾ H H OCH₂CH₃ D-238 E¹⁾ H HO-n-butyl D-239 E¹⁾ H H O-iso-butyl D-240 E¹⁾ H H O-2-butyl D-241 E¹⁾ HH O-2-ethylhexyl D-242 E¹⁾ H H N(CH₃)₂ D-243 E¹⁾ H H NPh₂ D-244 E¹⁾ HCF₃ H D-245 E¹⁾ CF₃ H H D-246 E¹⁾ H CF₃ OCH₃ D-247 E¹⁾ CF₃ H OCH₃ D-248E¹⁾ H CF₃ OCH₂CH₃ D-249 E¹⁾ CF₃ H OCH₂CH₃ D-250 E¹⁾ H CF₃ O-n-butylD-251 E¹⁾ CF₃ H O-n-butyl D-252 E¹⁾ H CF₃ O-iso-butyl D-253 E¹⁾ CF₃ HO-iso-butyl D-254 E¹⁾ H CF₃ O-2-butyl D-255 E¹⁾ CF₃ H O-2-butyl D-256E¹⁾ H CF₃ O-2-ethylhexyl D-257 E¹⁾ CF₃ H O-2-ethylhexyl D-258 E¹⁾ H CF₃N(CH₃)₂ D-259 E¹⁾ CF₃ H N(CH₃)₂ D-260 E¹⁾ H CF₃ NPh₂ D-261 E¹⁾ CF₃ HNPh₂ D-262 E¹⁾ H CN H D-263 E¹⁾ CN H H D-264 E¹⁾ CN H OCH₃ D-265 E¹⁾ HCN OCH₃ D-266 E¹⁾ CN H OCH₂CH₃ D-267 E¹⁾ H CN OCH₂CH₃ D-268 E¹⁾ CN HO-n-butyl D-269 E¹⁾ H CN O-n-butyl D-270 E¹⁾ CN H O-iso-butyl D-271 E¹⁾H CN O-iso-butyl D-272 E¹⁾ CN H O-2-butyl D-273 E¹⁾ H CN O-2-butyl D-274E¹⁾ CN H O-2-ethylhexyl D-275 E¹⁾ H CN O-2-ethylhexyl D-276 E¹⁾ CN HN(CH₃)₂ D-277 E¹⁾ H CN N(CH₃)₂ D-278 E¹⁾ CN H NPh₂ D-279 E¹⁾ H CN NPh₂

Blocking Layers

In addition to suitable hosts, an OLED device employing a phosphorescentmaterial often requires at least one exciton or hole blocking layers tohelp confine the excitons or electron-hole recombination centers to thelight-emitting layer comprising the host and phosphorescent material, orto reduce the number of charge carriers (electrons or holes). In oneembodiment, such a blocking layer would be placed between theelectron-transporting layer and the light-emitting layer. In this case,the ionization potential of the blocking layer should be such that thereis an energy barrier for hole migration from the host into theelectron-transporting layer, while the electron affinity should be suchthat electrons pass more readily from the electron-transporting layerinto the light-emitting layer comprising host and phosphorescentmaterial. It is further desired, but not absolutely required, that thetriplet energy of the blocking material be greater than that of thephosphorescent material. Suitable hole-blocking materials are describedin WO00/70655 and WO01/93642. Examples of useful materials are(1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene) (TPBI), bathocuproine(BCP) and bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III)(BAlq). Metal complexes other than Balq are also known to block holesand excitons as described in US20030068528. US20030175553 describes theuse of fac-tris(1-phenylpyrazolato-N,C2)iridium(III) (Irppz) in anelectron/exciton blocking layer.

Embodiments of the invention can provide advantageous features such asoperating efficiency, higher luminance, color hue, low drive voltage,and improved operating stability. Embodiments of the organometalliccompounds useful in the invention can provide a wide range of huesincluding those useful in the emission of white light (directly orthrough filters to provide multicolor displays).

General Device Architecture

The compounds of the present invention can be employed in many OLEDdevice configurations using small molecule materials, oligomericmaterials, polymeric materials, or combinations thereof. These includevery simple structures comprising a single anode and cathode to morecomplex devices, such as passive matrix displays comprised of orthogonalarrays of anodes and cathodes to form pixels, and active-matrix displayswhere each pixel is controlled independently, for example, with thinfilm transistors (TFTs).

There are numerous configurations of the organic layers. The essentialrequirements of an OLED are an anode, a cathode, and an organiclight-emitting layer located between the anode and cathode. Additionallayers may be employed as more fully described hereafter.

A typical structure, especially useful for of a small molecule device,is comprised of a substrate, an anode, a hole-injecting layer, ahole-transporting layer, a light-emitting layer, a hole- orexciton-blocking layer, an electron-transporting layer, and a cathode.These layers are described in detail below. Note that the substrate mayalternatively be located adjacent to the cathode, or the substrate mayactually constitute the anode or cathode. The organic layers between theanode and cathode are conveniently referred to as the organic ELelement. Also, the total combined thickness of the organic layers isdesirably less than 500 nm.

Substrate

The substrate can either be light transmissive or opaque, depending onthe intended direction of light emission. The light transmissiveproperty is desirable for viewing the EL emission through the substrate.Transparent glass or plastic is commonly employed in such cases. Thesubstrate can be a complex structure comprising multiple layers ofmaterials. This is typically the case for active matrix substrateswherein TFTs are provided below the OLED layers. It is still necessarythat the substrate, at least in the emissive pixilated areas, becomprised of largely transparent materials such as glass or polymers.For applications where the EL emission is viewed through the topelectrode, the transmissive characteristic of the bottom support isimmaterial, and therefore can be light transmissive, light absorbing orlight reflective. Substrates for use in this case include, but are notlimited to, glass, plastic, semiconductor materials, silicon, ceramics,and circuit board materials. Again, the substrate can be a complexstructure comprising multiple layers of materials such as found inactive matrix TFT designs. It is necessary to provide in these deviceconfigurations a light-transparent top electrode.

Anode

When the desired electroluminescent light emission (EL) is viewedthrough the anode, the anode should be transparent or substantiallytransparent to the emission of interest. Common transparent anodematerials used in this invention are indium-tin oxide (ITO), indium-zincoxide (IZO) and tin oxide, but other metal oxides can work including,but not limited to, aluminum- or indium-doped zinc oxide,magnesium-indium oxide, and nickel-tungsten oxide. In addition to theseoxides, metal nitrides, such as gallium nitride, and metal selenides,such as zinc selenide, and metal sulfides, such as zinc sulfide, can beused as the anode. For applications where EL emission is viewed onlythrough the cathode, the transmissive characteristics of the anode areimmaterial and any conductive material can be used, transparent, opaqueor reflective. Example conductors for this application include, but arenot limited to, gold, iridium, molybdenum, palladium, and platinum.Desired anode materials are commonly deposited by any suitable meanssuch as evaporation, sputtering, chemical vapor deposition, orelectrochemical means. Anodes can be patterned using well-knownphotolithographic processes. Optionally, anodes may be polished prior toapplication of other layers to reduce surface roughness so as tominimize shorts or enhance reflectivity.

Cathode

When light emission is viewed solely through the anode, the cathode usedin this invention can be comprised of nearly any conductive material.Desirable materials have good film-forming properties to ensure goodcontact with the underlying organic layer, promote electron injection atlow voltage, and have good stability. Useful cathode materials oftencontain a low work function metal (<4.0 eV) or metal alloy. One usefulcathode material is comprised of a Mg:Ag alloy wherein the percentage ofsilver is in the range of 1 to 20%, as described in U.S. Pat. No.4,885,221. Another suitable class of cathode materials includes bilayerscomprising the cathode and a thin electron-injection layer (EIL) incontact with an organic layer (e.g., an electron transporting layer(ETL)) which is capped with a thicker layer of a conductive metal. Here,the EIL preferably includes a low work function metal or metal salt, andif so, the thicker capping layer does not need to have a low workfunction. One such cathode is comprised of a thin layer of LiF followedby a thicker layer of Al as described in U.S. Pat. No. 5,677,572. An ETLmaterial doped with an alkali metal, for example, Li-doped Alq, isanother example of a useful EIL. Other useful cathode material setsinclude, but are not limited to, those disclosed in U.S. Pat. Nos.5,059,861, 5,059,862 and 6,140,763.

When light emission is viewed through the cathode, the cathode must betransparent or nearly transparent. For such applications, metals must bethin or one must use transparent conductive oxides, or a combination ofthese materials. Optically transparent cathodes have been described inmore detail in U.S. Pat. Nos. 4,885,211, 5,247,190, JP 3,234,963, U.S.Pat. Nos. 5,703,436, 5,608,287, 5,837,391, 5,677,572, 5,776,622,5,776,623, 5,714,838, 5,969,474, 5,739,545, 5,981,306, 6,137,223,6,140,763, 6,172,459, EP1076368, U.S. Pat. Nos. 6,278,236 and6,284,3936. Cathode materials are typically deposited by any suitablemethod such as evaporation, sputtering, or chemical vapor deposition.When needed, patterning can be achieved through many well known methodsincluding, but not limited to, through-mask deposition, integral shadowmasking as described in U.S. Pat. No. 5,276,380 and EP0732868, laserablation, and selective chemical vapor deposition.

Hole-Injecting Layer (HIL)

A hole-injecting layer may be provided between anode andhole-transporting layer. The hole-injecting material can serve toimprove the film formation property of subsequent organic layers and tofacilitate injection of holes into the hole-transporting layer. Suitablematerials for use in the hole-injecting layer include, but are notlimited to, porphyrinic compounds as described in U.S. Pat. No.4,720,432, plasma-deposited fluorocarbon polymers as described in U.S.Pat. No. 6,208,075, and some aromatic amines, for example, m-MTDATA(4,4′,4″-tris[(3-methylphenyl)phenylamino]triphenylamine). Alternativehole-injecting materials reportedly useful in organic EL devices aredescribed in EP0891121 and EP1029909. (Phthalocyanine copper complex)(CuPC) and(4,4′,4″-tris(N-(naphth-2-yl)-N-phenyl-amino)triphenylamine)(2-TNATA)can advantageously be used.

Hole-Transporting Layer (HTL)

The hole-transporting layer of the organic EL device contains at leastone hole-transporting compound such as an aromatic tertiary amine, wherethe latter is understood to be a compound containing at least onetrivalent nitrogen atom that is bonded only to carbon atoms, at leastone of which is a member of an aromatic ring. In one form the aromatictertiary amine can be an arylamine, such as a monoarylamine,diarylamine, triarylamine, or a polymeric arylamine. Exemplary monomerictriarylamines are illustrated in U.S. Pat. No. 3,180,730. Other suitabletriarylamines substituted with one or more vinyl radicals and/orcomprising at least one active hydrogen containing group are disclosedin U.S. Pat. Nos. 3,567,450 and 3,658,520. A more preferred class ofaromatic tertiary amines are those which include at least two aromatictertiary amine moieties as described in U.S. Pat. Nos. 4,720,432 and5,061,569. Such compounds include those represented by structuralformula

wherein Q¹ and Q² are independently selected aromatic tertiary aminemoieties and G is a linking group such as an arylene, cycloalkylene, oralkylene group of a carbon to carbon bond. In one embodiment, at leastone of Q¹ or Q² contains a polycyclic fused ring structure, e.g., anaphthalene. When G is an aryl group, it is conveniently a phenylene,biphenylene, or naphthalene moiety.

A useful class of triarylamines satisfying structural formula (A) andcontaining two triarylamine moieties is represented by structuralformula

where Q³ and Q⁴ each independently represents a hydrogen atom, an arylgroup, or an alkyl group or Q³ and Q⁴ together represent the atomscompleting a cycloalkyl group; and Q⁵ and Q⁶ each independentlyrepresents an aryl group, which is in turn substituted with a diarylsubstituted amino group, as indicated by structural formula

wherein Q⁷ and Q⁸ are independently selected aryl groups. In oneembodiment, at least one of Q⁷ or Q⁸ contains a polycyclic fused ringstructure, e.g., a naphthalene.

Another class of aromatic tertiary amines are the tetraaryldiamines.Desirable tetraaryldiamines include two diarylamino groups, such asindicated by formula (C), linked through an arylene group. Usefultetraaryldiamines include those represented by formula

wherein each Are is an independently selected arylene group, such as aphenylene or anthracene moiety, n is an integer of from 1 to 4, and Ar,Q⁹, Q¹⁰, and Q¹¹ are independently selected aryl groups. In a typicalembodiment, at least one of Ar, Q⁹, Q¹⁰, and Q¹¹ is a polycyclic fusedring structure, e.g., a naphthalene. The various alkyl, alkylene, aryl,and arylene moieties of the foregoing structural formulae (A), (B), (C),(D), can each in turn be substituted. Typical substituents include alkylgroups, alkoxy groups, aryl groups, aryloxy groups, and halogen such asfluoride, chloride, and bromide. The various alkyl and alkylene moietiestypically contain from about 1 to 6 carbon atoms. The cycloalkylmoieties can contain from 3 to about 10 carbon atoms, but typicallycontain five, six, or seven ring carbon atoms, e.g. cyclopentyl,cyclohexyl, and cycloheptyl ring structures. The aryl and arylenemoieties are usually phenyl and phenylene moieties.

The hole-transporting layer can be formed of a single or a mixture ofaromatic tertiary amine compounds. Specifically, one may employ atriarylamine, such as a triarylamine satisfying the formula (B), incombination with a tetraaryldiamine, such as indicated by formula (D).When a triarylamine is employed in combination with a tetraaryldiamine,the latter is positioned as a layer interposed between the triarylamineand the electron injecting and transporting layer. Illustrative ofuseful aromatic tertiary amines are the following:1,1-Bis(4-di-p-tolylaminophenyl)cyclohexane,1,1-bis(4-di-p-tolylaminophenyI)-4-phenylcyclohexane,N,N,N′,N′-tetraphenyl-4,4′″-diamino-1,1′:4′,1″:4″,1′″-guaterphenylbis(4-dimethylamino-2-methylphenyl)phenylmethane,1,4-bis[2-[4-[N,N-di(p-toly)amino]phenyl]vinyl]benzene (BDTAPVB),N,N,N′,N′-tetra-p-tolyl-4,4′-diaminobiphenyl,N,N,N′,N′-tetraphenyl-4,4′-diaminobiphenyl,N,N,N′,N′-tetra-1-naphthyl-4,4′-diaminobiphenyl,N,N,N′,N′-tetra-2-naphthyl-4,4′-diaminobiphenyl, N-phenylcarbazole,4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB),4,4′-bis[N-(1-naphthyl)-N-(2-naphthyl)amino]biphenyl (TNB),4,4′-bis[N-(1-naphthyl)-N-phenylamino]p-terphenyl,4,4′-bis[N-(2-naphthyl)-N-phenylamino]biphenyl,4,4′-bis[N-(3-acenaphthenyl)-N-phenylamino]biphenyl,1,5-bis[N-(1-naphthyl)-N-phenylamino]naphthalene,4,4′-bis[N-(9-anthryl)-N-phenylamino]biphenyl,4,4′-bis[N-(1-anthryl)-N-phenylamino]-p-terphenyl,4,4′-bis[N-(2-phenanthryl)-N-phenylamino]biphenyl,4,4′-bis[N-(8-fluoranthenyl)-N-phenylamino]biphenyl,4,4′-bis[N-(2-pyrenyl)-N-phenylamino]biphenyl,4,4′-bis[N-(2-naphthacenyl)-N-phenylamino]biphenyl,4,4′-bis[N-(2-perylenyl)-N-phenylamino]biphenyl,4,4′-bis[N-(1-coronenyl)-N-phenylamino]biphenyl,2,6-bis(di-p-tolylamino)naphthalene,2,6-bis[di-(1-naphthyl)amino]naphthalene,2,6-bis[N-(1-naphthyl)-N-(2-naphthyl)amino]naphthalene,N,N,N′,N′-tetra(2-naphthyl)-4,4″-diamino-p-terphenyl,4,4′-bis{N-phenyl-N-[4-(1-naphthyl)-phenyl]amino}biphenyl,2,6-bis[N,N-di(2-naphthyl)amino]fluorine,4,4′,4″-tris[(3-methylphenyl)phenylamino]triphenylamine (MTDATA), and4,4′-Bis[N-(3-methylphenyl)-N-phenylamino]biphenyl (TPD). A holetransport layer may be used to enhance conductivity. NPD and TPD areexamples of intrinsic hole transport layers. An example of a p-dopedhole transport layer is m-MTDATA doped with F₄-TCNQ at a molar ratio of50:1 as disclosed in U.S. Pat. No. 6,337,102 or DE10058578.

Another class of useful hole-transporting materials includes polycyclicaromatic compounds as described in EP1009041. Tertiary aromatic amineswith more than two amine groups may be used including oligomericmaterials. In addition, polymeric hole-transporting materials can beused such as poly(N-vinylcarbazole) (PVK), polythiophenes, polypyrrole,polyaniline, and copolymers such aspoly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) also calledPEDOT/PSS.

Fluorescent Light-Emitting Materials and Layers (LEL)

In addition to the phosphorescent materials, other light emittingmaterials may be used in the OLED device, including fluorescentmaterials. Although the term “fluorescent” is commonly used to describeany light emitting material, in this case we are referring to a materialthat emits light from a singlet excited state. Fluorescent materials maybe used in the same layer as the phosphorescent material, in adjacentlayers, in adjacent pixels, or any combination. Care must be taken notto select materials that will adversely affect the performance of thephosphorescent materials. One skilled in the art will understand thattriplet excited state energies of materials in the same layer as thephosphorescent material or in an adjacent layer must be appropriatelyset so as to prevent unwanted quenching. As more fully described in U.S.Pat. Nos. 4,769,292 and 5,935,721, the light-emitting layer (LEL) of theorganic EL element includes a luminescent fluorescent or phosphorescentmaterial where electroluminescence is produced as a result ofelectron-hole pair recombination in this region. The light-emittinglayer can be comprised of a single material, but more commonly consistsof a host material doped with a guest emitting material or materialswhere light emission comes primarily from the emitting materials and canbe of any color. The host materials in the light-emitting layer can bean electron-transporting material, as defined below, a hole-transportingmaterial, as defined above, or another material or combination ofmaterials that support hole-electron recombination. Fluorescent emittingmaterials are typically incorporated at 0.01 to 10% by weight of thehost material. The host and emitting materials can be smallnon-polymeric molecules or polymeric materials such as polyfluorenes andpolyvinylarylenes (e.g., poly(p-phenylenevinylene), PPV). In the case ofpolymers, small molecule emitting materials can be molecularly dispersedinto a polymeric host, or the emitting materials can be added bycopolymerizing a minor constituent into a host polymer. Host materialsmay be mixed together in order to improve film formation, electricalproperties, light emission efficiency, lifetime, or manufacturability.The host may comprise a material that has good hole-transportingproperties and a material that has good electron-transportingproperties.

Host and emitting materials known to be of use include, but are notlimited to, those disclosed in U.S. Pat. Nos. 4,768,292, 5,141,671,5,150,006, 5,151,629, 5,405,709, 5,484,922, 5,593,788, 5,645,948,5,683,823, 5,755,999, 5,928,802, 5,935,720, 5,935,721, and 6,020,078.

Metal complexes of 8-hydroxyquinoline and similar derivatives (FormulaE) constitute one class of useful host compounds capable of supportingelectroluminescence, and are particularly suitable for light emission ofwavelengths longer than 500 nm, e.g., green, yellow, orange, and red.

wherein M represents a metal; v is an integer of from 1 to 4; and ZZindependently in each occurrence represents the atoms completing anucleus having at least two fused aromatic rings. From the foregoing itis apparent that the metal can be monovalent, divalent, trivalent, ortetravalent metal. The metal can, for example, be an alkali metal, suchas lithium, sodium, or potassium; an alkaline earth metal, such asmagnesium or calcium; an earth metal, such aluminum or gallium, or atransition metal such as zinc or zirconium. Generally any monovalent,divalent, trivalent, or tetravalent metal known to be a useful chelatingmetal can be employed. ZZ completes a heterocyclic nucleus containing atleast two fused aromatic rings, at least one of which is an azole orazine ring. Additional rings, including both aliphatic and aromaticrings, can be fused with the two required rings, if required. To avoidadding molecular bulk without improving on function the number of ringatoms is usually maintained at 18 or less.

Illustrative of useful chelated oxinoid compounds are the following:

CO-1: Aluminum trisoxine [alias, tris(8-quinolinolato)aluminum(III)]

CO-2: Magnesium bisoxine [alias, bis(8-quinolinolato)magnesium(II)]

CO-3: Bis[benzo{f}-8-quinolinolato]zinc(II)

CO-4:Bis(2-methyl-8-quinolinolato)aluminum(III)-μ-oxo-bis(2-methyl-8-quinol-inolato)aluminum(III)

CO-5: Indium trisoxine [alias, tris(8-quinolinolato)indium]

CO-6: Aluminum tris(5-methyloxine) [alias,tris(5-methyl-8-quinolinolato) aluminum(III)]

CO-7: Lithium oxine [alias, (8-quinolinolato)lithium(I)]

CO-8: Gallium oxine [alias, tris(8-quinolinolato)gallium(III)]

CO-9: Zirconium oxine [alias, tetra(8-quinolinolato)zirconium(IV)]

Useful fluorescent emitting materials include, but are not limited to,derivatives of anthracene, tetracene, xanthene, perylene, rubrene,coumarin, rhodamine, and quinacridone, dicyanomethylenepyran compounds,thiopyran compounds, polymethine compounds, pyrilium and thiapyriliumcompounds, fluorene derivatives, periflanthene derivatives,indenoperylene derivatives, bis(azinyl)amine boron compounds,bis(azinyl)methane compounds, and carbostyryl compounds. Illustrativeexamples of useful materials include, but are not limited to, compoundsL1 to L52 described in U.S. Pat. No. 7,090,930B2.

Electron-Transporting Layer (ETL)

Preferred thin film-forming materials for use in forming theelectron-transporting layer of the organic EL devices of this inventionare metal chelated oxinoid compounds, including chelates of oxine itself(also commonly referred to as 8-quinolinol or 8-hydroxyquinoline). Suchcompounds help to inject and transport electrons and exhibit both highlevels of performance and are readily fabricated in the form of thinfilms. Exemplary of contemplated oxinoid compounds are those satisfyingstructural formula (E), previously described. Otherelectron-transporting materials include various butadiene derivatives asdisclosed in U.S. Pat. No. 4,356,429 and various heterocyclic opticalbrighteners as described in U.S. Pat. No. 4,539,507. Benzazolessatisfying structural formula (G) are also useful electron transportingmaterials. Triazines are also known to be useful as electrontransporting materials. Doping may be used to enhance conductivity.Alq₃is an example of an intrinsic electron transport layer. An exampleof an n-doped electron transport layer is BPhen doped with Li at a molarratio of 1:1, as disclosed in U.S. Pat. No. 6,337,102.

Deposition of Organic Layers

The organic materials mentioned above are suitably deposited by anymeans suitable for the form of the organic materials. In the case ofsmall molecules, they are conveniently deposited through thermalevaporation, but can be deposited by other means such as from a solventwith an optional binder to improve film formation. If the material issoluble or in oligomeric/polymeric form, solution processing is usuallypreferred e.g. spin-coating, ink-jet printing. Dendrimer substituentsmay be used to enhance the ability of small molecules to undergosolution processing. Patterned deposition can be achieved using shadowmasks, integral shadow masks (U.S. Pat. No. 5,294,870),spatially-defined thermal dye transfer from a donor sheet (U.S. Pat.Nos. 5,688,551, 5,851,709 and 6,066,357) and inkjet method (U.S. Pat.No. 6,066,357).

Encapsulation

Most OLED devices are sensitive to moisture or oxygen, or both, so theyare commonly sealed in an inert atmosphere such as nitrogen or argon,along with a desiccant such as alumina, bauxite, calcium sulfate, clays,silica gel, zeolites, alkaline metal oxides, alkaline earth metaloxides, sulfates, or metal halides and perchlorates. Methods forencapsulation and desiccation include, but are not limited to, thosedescribed in U.S. Pat. No. 6,226,890. In addition, barrier layers suchas SiO_(x), Teflon, and alternating inorganic/polymeric layers are knownin the art for encapsulation.

Devices fabricated in accordance with embodiments of the invention maybe incorporated into a wide variety of consumer products, including flatpanel displays, computer monitors, televisions, billboards, lights forinterior or exterior illumination and/or signalling, fully transparentdisplays, flexible displays, laser printers, cell phones, personaldigital assistants (PDAs), laptop computers, digital cameras,camcorders, viewfinders, micro-displays, vehicles, theatre or stadiumscreen, or a sign. Various control mechanism may be used to controldevices fabricated in accordance with the present invention, includingpassive matrix and active matrix.

Various features and aspects of the present invention are illustratedfurther in the examples that follow. While these examples are presentedto show one skilled in the art how to operate within the scope of thisinvention, they are not to serve as a limitation on the scope of theinvention where such scope is only defined in the claims. Unlessotherwise indicated in the following examples and elsewhere in thespecification and claims, all parts and percentages are by weight,temperatures are in degrees centigrade and pressures are at or nearatmospheric.

EXAMPLES Example 1

6,11-Dibromo-1,2,3,4-tetraphenyl-triphenylene can be prepared asdescribed in example 1 of PCT/EP2007/057408. 1.80 g (2.61 mmol)6,11-dibromo-1,2,3,4-tetraphenyl-triphenylene and 540 mg (5.60 mmol)sodium tert-butoxide are dissolved in 40 ml toluene. The reactionmixture is degassed with argon and 29 mg (0.13 mmol) palladium(II)acetate are added. Then 105 mg (0.520 mmol) tri-tert-butylphosphine areadded. A degassed solution of 1.77 g (8.08 mmol)naphthalen-1-yl-phenyl-amine in 15 ml toluene is added and the reactionmixture is heated at 90° C. for 3 h.

20 ml of a 1% sodium cyanide solution are added to the reaction mixtureand the reaction mixture is refluxed for 1 h. The reaction mixture isextracted with diethylether and then dichloromethane. The organic phaseis dried with magnesium sulfate. The solvent is removed in vacuum. Theproduct is purified by chromatography on silica gel withtoluene/cyclohexane (1/4). ¹H-NMR 300 MHz (CDCl₃) δ=6.50-6.90 (m, 22H),7.00-7.50 (m, 20H), 7.65-7.25 (m, 4H), 8.85 (d, J=8.1 Hz, 2H) 8.18 (d,J=8.8 Hz, 2H)

Example 2

a.) 4.44 g (43.5 mmol) ethynyl-benzene, 280 mg (1.45 mmol)copper(I)iodide and 340 mg (0.29 mmol) terakis(triphenylphosphine)palladium(0) are added to 10.0 g (14.5 mmol)6,11-dibromo-1,2,3,4-tetraphenyl-triphenylene in 200 ml piperidine. Thereaction mixture is stirred for 22 h at 130° C. under argon. The solidsare filtered off. The filtrate contains the target product and themonocoupling product. 2.96 g (26.6 mmol) ethynyl-benzene, 130 mg (0.725mmol) copper(I)iodide and 170 mg (0.145 mmol)terakis(triphenylphosphine) palladium(0) are added to the filtrate inpiperidine, The reaction mixture is stirred for 48 h at 130° C. underargon. The solids are filtered off. The solvent is removed in vacuum andthe product is decocted 2 times with n-hexane.

b) A mixture of 3.00 g (4.09 mmol) of the product of example 2a and 16.6g (65.5 mmol) iodine are dissolved in 50 ml dimethyl sulfoxide (DMSO).The reaction mixture is stirred for 21 h at 160° C. and poured intowater and the water phase is extracted with dichloromethane. The organicphase is washed with a 10% sodium thiosulfate solution. The organicphase is dried with sodium sulfate and the solvent is removed in vacuum.The product is isolated by column chromatography on silica gel withtoluene.

c) 540 mg (5.00 mmol) benzene-1,2-diamine are added to 2.00 g (2.51mmol) of the product of example 2b in 80 ml ethanol and 40 mlchloroform. 12 drops sulfuric acid are added and the reaction mixture isrefluxed for 4 days. The product is filtered off, washed with ethanoland 20% hydrochloric acid and soxhlet extracted with chloroform. Meltingpoint: 288° C.

Example 3

3.00 g (4.35 mmol) 6,11-dibromo-1,2,3,4-tetraphenyl-triphenylene and3.90 g (9.56 mmol)2,3-diphenyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-guinoxaline(example 5b of PCT/EP2008/053251) are dissolved in a mixture of 20 mldioxane and 80 ml toluene. The solution is degassed with argon. 107 mg(0.261 mmol) dicyclohexyl-(2′,6′-dimethoxy-biphenyl-2-yl)-phosphane and9.8 mg (0.043 mmol) palladium(II) acetate are added. The solution isdegassed with argon. A degassed solution of 5.27 g (21.7 mmol) potassiumphosphate tribasic monohydrate (K₃PO₄*H₂O) in 16 ml water is added. Thereaction mixture is stirred under argon for 18 h at 90° C. The productis filtered off, washed with toluene, dissolved in dichloromethane andis filtered on silica gel. Melting point: 367° C.

Example 4

A mixture of 20 ml dioxane and 80 ml toluene is added to 3.00 g (4.35mmol) 6,11-dibromo-1,2,3,4-tetraphenyl-triphenylene and 1.89 g (9.56mmol) 3-biphenyl boronic acid. The mixture is degassed with argon. 107mg (0.261 mmol) dicyclohexyl-(2′,6′-dimethoxy-biphenyl-2-yl)-phospheneand 9.8 mg (0.043 mmol) palladium(II) acetate are added. The solution isdegassed with argon. A degassed solution of 5.27 g (21.7 mmol) potassiumphosphate tribasic monohydrate (K₃PO₄*H₂O) in 16 ml water is added. Thereaction mixture is stirred under argon for 18 h at 90° C. The productis filtered off, washed with toluene and soxhlet extracted withdichloromethane. Melting point: 334° C.

Example 5

The product of example 5 is prepared in analogy to the product ofexample 1. Xylene is used instead of toluene as solvent. Melting point:336° C.

Example 6

The product of example 6 is prepared in analogy to the product ofexample 4. Glass transition point: 211° C. ¹H-NMR 300 MHz (CDCl₃) δ=8.74(d, J=8.3 Hz, 2H), 7.98-8.21 (m, 18H), 7.81 (dd, J=8.2, 1.7 Hz, 2H),7.10-7.28 (m, H+CHCl₃), 6.83-6.93 (m, 6H), 6.67-6.70 (m, 4H)

Example 7

a.) 5.00 g (7.24 mmol) 6,11-dibromo-1,2,3,4-tetraphenyl-triphenylene aredissolved in 30 ml water free THF (tetrahydrofurane) under argon. 6.4 ml(15.9 mmol) n-butyl lithium solution (2.5 M in hexane) are slowly addedto this mixture at −78° C. After adding the n-butyl lithium solution thereaction mixture is stirred for 10 minutes. 5.29 g (72.4 mmol) DMF(N,N-dimethyl-formamide) are added. The reaction mixture is stirred for10 min at −78° C. and is then warmed up to 25° C. The reaction mixtureis poured into water and the water phase is extracted withdichloromethane. The organic phase is dried with sodium sulfate and thesolvent is removed in vacuum. After a column chromatography on silicagel with toluene/hexane 1/1 the product is isolated.

b.) 800 mg (3.74 mmol) (2-nitro-phenyl)-phenyl-amine and 1.77 g (10.2mmol) sodium dithionite are added to 1.00 g (1.70 mmol) of the productof example 7a in 40 ml ethanol, under argon. The reaction mixture isrefluxed under argon for 48 h, poured into water and the water phase isextracted with dichloromethane. The solvent was removed in vacuum. Thedried product contains a mixture of target product and themonobenzoimidazole intermediate. 400 mg (1.87 mmol)(2-nitro-phenyl)-phenyl-amine and 900 mg (5.1 mmol) sodium dithioniteare added to the crude product in 40 ml ethanol under argon. Thereaction mixture is refluxed under argon for 48 h, cooled to 25° C., theproduct is filtered off and isolated after a column chromatography onsilica gel with toluene/ethanol 6/1. Melting point: 361° C.

Example 8

6,11-Dibromo-1,2,3,4-tetraphenyl-triphenylene can be prepared accordingto example 1 of PCT/EP2007/057408. The product of example 8 is preparedin analogy to the product of example 5. Melting point: 375° C.

Comparative Example 1

a) 21.0 g (0.131 mol) bromine in 30 ml phosphoric acid trimethyl esterare added to 10 g (43.8 mmol) triphenylene in 150 ml phosphoric acidtrimethyl ester at 25° C. under nitrogen. The reaction mixture isstirred at 85° C. under nitrogen for 5 h, cooled to 25° C. and thesolids are filtered off. The filtrate is left over night at 25° C. Theformed precipitate is filtered off. The precipitate contains mostlybisbromid (mixture of isomers) B and lower quantities of mono bromide A.

b) The product of comparative example 1a is reacted with carbazole inanalogy to example 5. The products of this example are separated bycolumn chromatography on silica gel with n-hexane/toluene 8/2. Product Ais isolated as a single isomer. Product B is a mixture of inseparableisomers. Melting point of product A: 217° C.

As evident from the table below the glass transition points of thecompounds of the present invention are higher than those of the priorart compounds, which fact indicates that the compounds of the presentinvention have a higher device stability (life time) than the prior artcompounds.

Example T_(g) Example 5 193° C. Example 8 202° C. Comparison Example 1 91° C. Product A Comparison Example 1 129° C. Product B

DEVICE FABRICATION AND APPLICATION EXAMPLES

Devices are fabricated by thermal evaporation in high vacuum (<10⁻⁶mbar). The anode consists of ca. 1200 Å of indium tin oxide (ITO)previously deposited on a glass substrate. The cathode consists of 10 Åof LiF followed by 1000 Å of Al. All devices are tested immediatelyafter preparation, without encapsulation, in the nitrogen atmosphere ofa glove box (<1 ppm of H₂O and O₂). All materials used are of sublimedquality.

Application Example 1

The organic stack consists sequentially, from the ITO surface, of 600 Åof 2-TNATA (4,4′,4″-tris(N-(naphth-2-yl)-N-phenyl-amino)triphenylamine)as the hole injection layer (HIL), 300 Å of4,4′-bis[N-(1-naphtyl)-N-phenylamino]biphenyl (α-NPD) as the holetransport layer. The emissive layer consists of 300 Å of material fromExample 5, Example 8, Product A and Product B, respectively (as host,Application Example 1a, 1b, 1c and 1d in the table below), in all casesdoped with 10% of red emitter bis(1-(phenyl)isoquinoline) iridium (III)acetylanetonate ((abbreviation: Ir(piq)₂(acac), guest), followed by 10nm of TPBI (1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene) as thehole blocking layer and 30 nm of Alq₃(tris-(8-hydroxy-chinolinato)-aluminium) as the electron transportlayer.

Current efficiency, along with the onset voltage (C at 1000 cd/m²), CIEvalues and maximum luminance measured for devices prepared as above isreported in the table below:

Appl. Max Exam- C. Eff/1000 V/1000 CIE Lum/ ple HOST cd/m² cd/m² (x, y)cd/m² 1a Cpd. of 1.8 10.2 0.67, 0.31 2600 Example 5 1b Cpd. of 5.6 8.30.67, 0.31 8900 Example 8 1c Product A 3.4 9.9 0.67, 0.31 3100 1dProduct B 0.2 17.0 0.67, 0.31 300

As reported in the table above, the devices of Application Example 1aand 1b comprising the compounds of Example 5 and 8 show improved currentefficiency in respect to the devices of Application Example 1c and 1dcomprising comparative products A and B. In particular, onset voltage ofthe device of Application Example 1b comprising the Compound of Example8 is only 8.3 V, which is a quite low value, unmatched by the devices ofApplication Examples 1c and d using comparative products A and B in asimilar device set-up.

Application Example 2

The organic stack consists sequentially, from the ITO surface, of 600 Åof 2-TNATA (4,4′,4′-tris(N-(naphth-2-yl)-N-phenyl-amino)triphenylamine)as the hole injection layer (HIL), 300 Å of4,4′-bis[N-(1-naphtyl)-N-phenylamino]biphenyl (α-NPD) as the holetransport layer. The emissive layer consists of 300 Å of material fromExample 5, Example 8, Product A and Product B, respectively (as host,Application Example 2a, 2b, 2c and 2d in the table below), in all casesdoped with 10% of red emitter(acetylanetonato)bis(2,3,5-triphenylpyrazinato)iridium(III)(abbreviation: Ir(tppr)₂(acac); guest), followed by 10 nm of TPBI(1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene) as the hole blockinglayer and 30 nm of Alq₃ (tris-(8-hydroxy-chinolinato)-aluminium) as theelectron transport layer.

Current efficiency, along with the onset voltage (C at 1000 cd/m²), CIEvalues and maximum luminance measured for devices prepared as above isreported in the table below:

Appl. Max Exam- C. Eff@1000 V@1000 CIE Lum/ ple HOST cd/m² cd/m² (x, y)cd/m² 2a Cpd. of 4.9 9.4 0.64, 0.34 5300 Example 5 2b Cpd. of 6.1 8.70.64, 0.34 7800 Example 8 2c Product A 4 10.0 0.64, 0.34 3000 2d ProductB 0.7 14.2 0.64, 0.34 850

As reported in the table above, the devices of Application Example 2aand 2b comprising the compounds of Example 5 and 8 show improvedcurrent. efficiency and maximal luminance in respect to the devices ofApplication Example 2c and 2d comprising comparative products A and B.In particular, onset voltage of the devices of Application Example 2aand 2b comprising the compounds of Example 5 and 8, respectively is muchlower than that of the devices of Application Examples 2c and 2dcomprising the comparative products A and B.

Application Example 3

The organic stack consists sequentially, from the ITO surface, of 100 Åof CuPC (Phthalocyanine copper complex) as the hole injection layer(HIL), 300 Å of 4,4′-bis[N-(1-naphtyl)-N-phenylamino]biphenyl (α-NPD) asthe hole transport layer. The emissive layer consists of 300 Å ofmaterial from Example 5, Example 8, and product A respectively (as host,Application Examples 3a, 3b and 3c in the table below), in all casesdoped with 6% of green emitter tris(2-phenyl-pyridyl)iridium complex(guest), followed by 10 nm of BAlq(bis(2-methyl-8-quinolinolato)-4-(phenyl-phenolato)aluminium-(III) asthe hole blocking layer and 30 nm of Alq₃(tris-(8-hydroxy-chinolinato)-aluminium) as the electron transportlayer.

Current efficiency, along with the onset voltage (C at 1000 cd/m²), CIEvalues and maximum luminance measured for devices prepared as above isreported in the table below:

Appl. Max Exam- C. Eff@1000 V@1000 CIE Lum/ ple HOST cd/m² cd/m² (x, y)cd/m² 3a Cpd. of 14.8 9.8 0.32, 0.60 3100 Example 5 3b Cpd. of 5.1 8.00.32, 0.60 7500 Example 8 3c Product A 2.5 10.4 0.32, 0.60 3000

As reported in the table above, the devices of Application Example 3aand 3b comprising the materials from Example 5 and 8 show improvedcurrent efficiency and maximal luminance in respect to the device ofApplication Example 3c comprising comparative product A, along withlower onset voltage. In particular, the device of application Example 3acomprising the compound of Example 5, shows a current efficiency of 14.8Cd/A at 1000 Cd/m², which is significantly higher than the currentefficiency of the device of Application Example 3c comprisingcomparative product A.

1. An electronic device, comprising a compound of the formula

selected from the group consisting of

wherein R¹ and R² are independently of each other a C₆-C₂₄aryl group, ora C₂-C₃₀heteroaryl group, which can optionally be substituted, R³ and R⁴are independently of each other hydrogen, a C₁-C₂₅alkyl group, aC₆-C₂₄aryl group, or a C₂-C₃₀heteroaryl group, which can optionally besubstituted, X¹ is

—NA¹A^(1′), —P(═O)A⁴A^(4′), —SiA⁶A⁷A⁸, a C₁₀-C₂₈aryl group, which canoptionally be substituted, or a C₂-C₃₀heteroaryl group, which canoptionally be substituted, X² is

—NA²A^(2′), —P(═O)A⁵A^(5′), —SiA^(6′)A^(7′)A^(8′), a C₁₀-C₂₈aryl group,which can optionally be substituted, or a C₂-C₃₀heteroaryl group, whichcan optionally be substituted, Ar and Ar′ are independently of eachother C₆-C₁₄aryl, selected from the group consisting of phenyl, andnaphthyl, which may optionally be substituted by one or more groupsselected from C₁-C₂₅alkyl, which may optionally be interrupted by —O—,or C₁-C₂₅alkoxy, L¹ and L² are independently of each other a singlebond, or a bridging unit BU selected from the group consisting of

R⁵ and R⁶ are independently of each other halogen, or an organicsubstituent, or R⁵ and R⁶, which are adjacent to each other, togetherform an aromatic, or heteroaromatic ring, or ring system, which canoptionally be substituted, A¹, A², A^(1′) and A^(2′) are independentlyof each other a C₆-C₂₄aryl group, a C₂-C₃₀heteroaryl group, which canoptionally be substituted, or A¹ and A^(1′) or A² and A^(2′) or A³ andA^(3′) together with the nitrogen atom to which they are bonded form aheteroaromatic ring, or ring system selected from the group consistingof

wherein m′ is 0, 1, or 2; A⁴, A^(4′), A⁶, A⁷, A⁸, A⁵, A^(5′), A^(6′),A^(7′), and A^(8′) are independently of each other a C₆-C₂₄aryl group,or a C₂-C₃₀heteroaryl group, which can optionally be substituted, m1 canbe the same or different at each occurrence and is 0, 1, 2, 3, or 4,R¹¹⁹ and R¹²⁰ are independently of each other C₁-C₁₈alkyl, C₁-C₁₈alkylwhich is substituted by E and/or interrupted by D, C₆-C₂₄aryl,C₆-C₂₄aryl which is substituted by G, C₂-C₂₀heteroaryl, C₂-C₂₀heteroarylwhich is substituted by G, C₂-C₁₈alkenyl, C₂-C₁₈alkynyl, C₁-C₁₈alkoxy,C₁-C₁₈alkoxy which is substituted by E and/or interrupted by D, orC₇-C₂₅aralkyl, or R¹¹⁹ and R¹²⁰ together form a group of formula═CR¹²¹R¹²², wherein R¹²¹ and R¹²² are independently of each other H,C₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by E and/or interrupted byD, C₆-C₂₄aryl, C₆-C₂₄aryl which is substituted by G, orC₂-C₂₀heteroaryl, or C₂-C₂₀heteroaryl which is substituted by G, or R¹¹⁹and R¹²⁰ together form a five or six membered ring, which optionally canbe substituted by C₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by Eand/or interrupted by D, C₆-C₂₄aryl, C₆-C₂₄aryl which is substituted byG, C₂-C₂₀heteroaryl, C₂-C₂₀heteroaryl which is substituted by G,C₂-C₁₈alkenyl, C₂-C₁₈alkynyl, C₁-C₁₈alkoxy, C₁-C₁₈alkoxy which issubstituted by E and/or interrupted by D, C₇-C₂₅aralkyl, or —C(═O)—R¹²⁷,and R¹²⁷ is H; C₆-C₁₈aryl; C₆-C₁₈aryl which is substituted byC₁-C₁₈alkyl, or C₁-C₁₈alkoxy; C₁-C₁₈alkyl; or C₁-C₁₈alkyl which isinterrupted by —O—, D is —CO—, —COO—, —S—, —SO—, —SO₂—, —O—, —NR⁶⁵—,—SiR⁷⁰R⁷¹—, —POR⁷²—, —CR⁶³═CR⁶⁴—, or —C≡C—, and E is —OR⁶⁹, —SR⁶⁹,—NR⁶⁵R⁶⁶, —COR⁶⁸, —COOR⁶⁷, —CONR⁶⁵R⁶⁶, —CN, or halogen, G is E, orC₁-C₁₈alkyl, R⁶³ and R⁶⁴ are independently of each other C₆-C₁₈aryl;C₆-C₁₈aryl which is substituted by C₁-C₁₈alkyl, C₁-C₁₈alkoxy;C₁-C₁₈alkyl; or C₁-C₁₈alkyl which is interrupted by —O—; or R⁶⁵, R^(65′)and R⁶⁶ are independently of each other C₆-C₁₈aryl; C₆-C₁₈aryl which issubstituted by C₁-C₁₈alkyl, C₁-C₁₈alkoxy; C₁-C₁₈alkyl; or C₁-C₁₈alkylwhich is interrupted by —O—; or R⁶⁵ and R⁶⁶ together form a five or sixmembered ring, R⁶⁷ is C₆-C₁₈aryl; C₆-C₁₈aryl which is substituted byC₁-C₁₈alkyl, or C₁-C₁₈alkoxy; C₁-C₁₈alkyl; or C₁-C₁₈alkyl which isinterrupted by —O—, R⁶⁸ is H; C₆-C₁₈aryl; C₆-C₁₈aryl which issubstituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; C₁-C₁₈alkyl; or C₁-C₁₈alkylwhich is interrupted by —O—, R⁶⁹ is C₆-C₁₈aryl; C₆-C₁₈aryl, which issubstituted by C₁-C₁₈alkyl, C₁-C₁₈alkoxy; C₁-C₁₈alkyl; or C₁-C₁₈alkylwhich is interrupted by —O—, R⁷⁰ and R⁷¹ are independently of each otherC₁-C₁₈alkyl, C₆-C₁₈aryl, or C₆-C₁₈aryl, which is substituted byC₁-C₁₈alkyl, and R⁷² is C₁-C₁₈alkyl, C₆-C₁₈aryl, or C₆-C₁₈aryl, which issubstituted by C₁-C₁₈alkyl; R⁴¹ can be the same or different at eachoccurrence and is Cl, F, CN, NR⁴⁵R^(45′), a C₁-C₂₅alkyl group, aC₄-C₁₈cycloalkyl group, a C₁-C₂₅alkoxy group, in which one or morecarbon atoms which are not in neighbourhood to each other could bereplaced by —NR⁴⁵—, —O—, —S—, —C(═O)—O—, or —O—C(═O)—O—, and/or whereinone or more hydrogen atoms can be replaced by F, a C₆-C₂₄aryl group, ora C₆-C₂₄aryloxy group, wherein one or more carbon atoms can be replacedby O, S, or N, and/or which can be substituted by one or morenon-aromatic groups R⁴¹, or two or more groups R⁴¹ form a ring system;R⁴⁵ and R^(45′) are independently of each other a C₁-C₂₅alkyl group, aC₄-C₁₈cycloalkyl group, in which one or more carbon atoms which are notin neighbourhood to each other could be replaced by —NR^(45″)—, —O—,—S—, —C(═O)—O—, or, —O—C(═O)—O—, and/or wherein one or more hydrogenatoms can be replaced by F, a C₆-C₂₄aryl group, or a C₆-C₂₄aryloxygroup, wherein one or more carbon atoms can be replaced by O, S, or N,and/or which can be substituted by one or more non-aromatic groups R⁴¹,R^(45″) is a C₁-C₂₅alkyl group, or a C₄-C₁₈cycloalkyl group, and m canbe the same or different at each occurrence and is 0, 1, 2, or
 3. 2. Theelectronic device according to claim 1, wherein the electronic device isan electroluminescent (EL) device.
 3. The EL device according to claim2, comprising a compound of the formula I, wherein R¹ and R² areindependently of each other a C₆-C₂₄aryl group, or a C₂-C₃₀heteroarylgroup, which can optionally be substituted, and R³ is hydrogen and R⁴ isa C₁-C₂₅alkyl group, a C₆-C₂₄aryl group, or a C₂-C₃₀heteroaryl group,which can optionally be substituted, or R³ and R⁴ are independently ofeach other a C₁-C₂₅alkyl group, a C₆-C₂₄aryl group, or aC₂-C₃₀heteroaryl group, which can optionally be substituted.
 4. The ELdevice according to claim 3, comprising a compound of the formula I,wherein R¹ and R² are a group of formula

and R³ is hydrogen and R⁴ is a C₁-C₂₅alkyl group, or a group of formula

or R³ and R⁴ are a group of formula

wherein R⁷, R⁸ and R⁹ are independently of each other H, C₁-C₁₈alkyl,C₁-C₁₈alkoxy, or C₁-C₁₈alkyl which is interrupted by O.
 5. The EL deviceaccording to claim 2, comprising a compound of the formula (I), wherein-L¹-X¹ and -L²-X² are independently of each other a group of formula—NA¹A^(1′), or a group

wherein A¹, A^(1′), A³ and A^(3′) are independently of each other aC₆-C₂₄aryl group, or a C₂-C₃₀heteroaryl group, which can optionally besubstituted, selected from the group consisting of phenyl, naphthyl,anthryl, biphenylyl, 2-fluorenyl, phenanthryl, and perylenyl, which canoptionally be substituted, said groups being selected from the groupconsisting of

or A¹ and A^(1′), or A³ and A^(3′) together with the nitrogen atom towhich they are bonded form a heteroaromatic ring, or ring system,selected from the group consisting of

wherein m′ is 0, 1, or 2; m1 can be the same or different at eachoccurrence and is 0, 1, 2, 3, or 4; R¹¹⁶, R¹¹⁷ and R^(117′) areindependently of each other H, halogen, —CN, C₁-C₁₈alkyl, C₁-C₁₈alkylwhich is substituted by E and/or interrupted by D, C₆-C₂₄aryl,C₆-C₂₄aryl which is substituted by G, C₂-C₂₀heteroaryl, C₂-C₂₀heteroarylwhich is substituted by G, C₂-C₁₈alkenyl, C₂-C₁₈alkynyl, C₁-C₁₈alkoxy,C₁-C₁₈alkoxy which is substituted by E and/or interrupted by D,C₇-C₂₅aralkyl, —C(═O)—R¹²⁷, —C(═O)OR¹²⁷, or —C(═O)NR¹²⁷R¹²⁶, orsubstituents R¹¹⁶, R¹¹⁷ and R^(117′), which are adjacent to each other,can form a ring, R¹¹⁹ and R¹²⁰ are, independently of each otherC₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by E and/or interrupted byD, C₆-C₂₄aryl, C₆-C₂₄aryl which is substituted by G, C₂-C₂₀heteroaryl,C₂-C₂₀heteroaryl which is substituted by G, C₂-C₁₈alkenyl,C₂-C₁₈alkynyl, C₁-C₁₈alkoxy, C₁-C₁₈alkoxy which is substituted by Eand/or interrupted by D, or C₇-C₂₅aralkyl, or R¹¹⁹ and R¹²⁰ togetherform a group of formula ═CR¹²¹R¹²², wherein R¹²¹ and R¹²² areindependently of each other H, C₁-C₁₈alkyl, C₁-C₁₈alkyl which issubstituted by E and/or interrupted by D, C₆-C₂₄aryl, C₆-C₂₄aryl whichis substituted by G, or C₂-C₂₀heteroaryl, or C₂-C₂₀heteroaryl which issubstituted by G, or R¹¹⁹ and R¹²⁰ together form a five or six memberedring, which optionally can be substituted by C₁-C₁₈alkyl, C₁-C₁₈alkylwhich is substituted by E and/or interrupted by D, C₆-C₂₄aryl,C₆-C₂₄aryl which is substituted by G, C₂-C₂₀heteroaryl, C₂-C₂₀heteroarylwhich is substituted by G, C₂-C₁₈alkenyl, C₂-C₁₈alkynyl, C₁-C₁₈alkoxy,C₁-C₁₈alkoxy which is substituted by E and/or interrupted by D,C₇-C₂₅aralkyl, or —C(═O)—R¹²⁷, R¹²⁶ and R¹²⁷ are independently of eachother H; C₆-C₁₈aryl; C₆-C₁₈aryl which is substituted by C₁-C₁₈alkyl, orC₁-C₁₈alkoxy; C₁-C₁₈alkyl; or C₁-C₁₈alkyl which is interrupted by —O—,BU is

wherein R⁴¹ can be the same or different at each occurrence and is Cl,F, CN, NR⁴⁵R^(45′), a C₁-C₂₅alkyl group, a C₄-C₁₈cycloalkyl group, aC₁-C₂₅alkoxy group, in which one or more carbon atoms which are not inneighbourhood to each other could be replaced by —NR⁴⁵—, —O—, —S—,—C(═O)—O—, or —O—C(═O)—O—, and/or wherein one or more hydrogen atoms canbe replaced by F, a C₆-C₂₄aryl group, or a C₆-C₂₄aryloxy group, whereinone or more carbon atoms can be replaced by O, S, or N, and/or which canbe substituted by one or more non-aromatic groups R⁴¹, or two or moregroups R⁴¹ form a ring system; R⁴⁵ and R^(45′) are independently of eachother a C₁-C₂₅alkyl group, a C₄-C₁₈cycloalkyl group, in which one ormore carbon atoms which are not in neighbourhood to each other could bereplaced by —NR^(45″)—, —O—, —S—, —C(═O)—O—, or, —O—C(═O)—O—, and/orwherein one or more hydrogen atoms can be replaced by F, a C₆-C₂₄arylgroup, or a C₆-C₂₄aryloxy group, wherein one or more carbon atoms can bereplaced by O, S, or N, and/or which can be substituted by one or morenon-aromatic groups R⁴¹, R^(45″) is a C₁-C₂₅alkyl group, or aC₄-C₁₈cycloalkyl group, and m1 can be the same or different at eachoccurrence and is 0, 1, 2, 3 or 4; or -L¹-X¹ and -L²-X² areindependently of each other a group

wherein R¹¹⁶, R^(116′), R¹¹⁷ and R^(117′) are as defined above, D is—CO—, —COO—, —S—, —SO—, —SO₂—, —O—, —NR⁶⁵—, —SiR⁷⁰R⁷¹—, —POR⁷²—,—CR⁶³═CR⁶⁴—, or —C≡C—, and E is —OR⁶⁹, —SR⁶⁹, —NR⁶⁵R⁶⁶, —COR⁶⁸, —COOR⁶⁷,—CONR⁶⁵R⁶⁶, —CN, or halogen, G is E, or C₁-C₁₈alkyl; or -L¹-X¹ and-L²-X² are independently of each other a group

wherein R¹¹⁶, R¹¹⁷ and R^(117′) are as defined above.
 6. The EL deviceaccording to claim 3, comprising a compound of the formula (I), wherein-L¹-X¹ and -L²-X² are independently of each other a group of formula

—NA¹A^(1′), or a group

wherein A¹, A^(1′), A³ and A^(3′) are independently of each other

or A³ and A^(3′) together with the nitrogen atom to which they arebonded form a group of formula

R¹¹⁶ and R¹¹⁷ are independently of each other C₁-C₂₅alkyl, which mayoptionally be interrupted by —O—, or C₁-C₂₅alkoxy; Bu is

wherein R⁴¹ can be the same or different at each occurrence and isC₁-C₂₅alkyl, which may optionally be interrupted by —O—, orC₁-C₂₅alkoxy; and m1 is 0, 1, or
 2. 7. The EL device according to claim2, comprising a compound selected from

Compound X¹ = X² A1 HE-1 A2 HE-2 A3 HE-3 A4 HE-4 A5 HE-5 A6 HE-6 A7 HE-7A8 HE-8 A9 HE-9 A10 AR-1 A11 AR-2 A12 AR-3 A13 AR-4 A14 AM-1 A15 AM-2A17 AM-3 A18 AM-4 A19 AM-5 A20 AM-6 A21 AM-7

Compound X¹ = X² B1 HE-1 B2 HE-2 B3 HE-3 B4 HE-4 B5 HE-5 B6 HE-6 B7 HE-7B8 HE-8 B9 HE-9 B10 AR-1 B11 AR-2 B12 AR-3 B13 AR-4 B14 AM-1 B15 AM-2B17 AM-3 B18 AM-4 B19 AM-5 B20 AM-6 B21 AM-7

Compound X¹ = X² C1 HE-1 C2 HE-2 C3 HE-3 C4 HE-4 C5 HE-5 C6 HE-6 C7 HE-7C8 HE-8 C9 HE-9 C10 AR-1 C11 AR-2 C12 AR-3 C13 AR-4 C14 AM-1 C15 AM-2C17 AM-3 C18 AM-4 C19 AM-5 C20 AM-6 C21 AM-7

Compound X¹ = X² D1 HE-1 D2 HE-2 D3 HE-3 D4 HE-4 D5 HE-5 D6 HE-6 D7 HE-7D8 HE-8 D9 HE-9 D10 AR-1 D11 AR-2 D12 AR-3 D13 AR-4 D14 AM-1 D15 AM-2D17 AM-3 D18 AM-4 D19 AM-5 D20 AM-6 D21 AM-7


8. The electroluminescent device according to claim 2, comprising acathode, an anode, and therebetween a light emitting layer containing ahost material and a phosphorescent light-emitting material, wherein thehost material is a compound of formula I.
 9. A compound of the formula

selected from the group consisting of

wherein X¹ is

—NA¹A^(1′), —P(═O)A⁴A^(4′), —SiA⁶A⁷A⁸, or a C₁₀-C₂₈aryl group, which canoptionally be substituted, or a C₂-C₃₀heteroaryl group, which canoptionally be substituted, X² is

—NA²A^(2′), —P(═O)A⁵A^(5′), or —SiA^(6′)A^(7′)A^(8′), or a C₁₀-C₂₈arylgroup, which can optionally be substituted, or a C₂-C₃₀heteroaryl group,which can optionally be substituted, R¹ and R² are independently of eachother a C₆-C₂₄ aryl group, or a C₂-C₃₀ heteroaryl group, which canoptionally substituted, R³ and R⁴ are independently of each otherhydrogen, a C₁-C₂₅ alkyl group, a C₆-C₂₄ aryl group, or a C₂-C₃₀heteroaryl group, which can optionally be substituted, R⁵ and R⁶ areindependently of each other halogen, or an organic substituent, or R⁵and R⁶, which are adjacent to each other, together form an aromaticsubstituent, or heteroaromatic ring, or ring system, which canoptionally be substituted, and m can be the same or different at eachoccurrence and is 0, 1, 2 or
 3. 10. (canceled)
 11. A process for thepreparation of compounds of the formula I according to claim 9, whereinX¹ and X² are independently of each other —NA¹A^(1′),

m′ is 0, 1, or 2; which comprises reacting a compound of formula

wherein X¹⁰ stands for a halogen, selected from the group consisting ofbromo, and iodo, with a compound of formula HNA¹A^(1′),

in the presence of a base and a catalyst in a solvent, wherein A¹ andA¹′ are independently of each other a C₆-C₂₄ aryl group, a C₂-C₃₀heteroaryl group, which can optionally be substituted, or A¹ and A^(1′)together with the nitrogen atom to which they are bonded from aheteroaromatic ring, or ring system selected from the group consistingof

wherein m′ is 0, 1, or 2; m1 can be the same or different at eachoccurrence and is 0, 1, 2, 3, or 4, R⁴¹ can be the same or different ateach occurrence and is Cl, F, CN, NR⁴⁵R^(45′), a C₁-C₂₃ alkyl group, aC₄-C₁₈ cycloalkyl group, a C₁-C₂₅ alkoxy group, in which one or morecarbon atoms which are not in neighborhood to each other could bereplaced by —NR⁴⁵—, —O—, —S—, —C(═O)—O—, or —O—C(═O)—O—, and/or whereinone or more hydrogen atoms can be replaced by F, a C₆-C₂₄aryl group, ora C₆-C₂₄aryloxy group, wherein one or more carbon atoms can be replacedby O, S, or N, and/or which can be substituted by one or morenon-aromatic groups R⁴¹, or two or more groups R⁴¹ form a ring system;R⁴⁵ and R^(45′) are independently of each other a C₁-C₂₅alkyl group, aC₄-C₁₈cycloalkyl group, in which one or more carbon atoms which are notin neighborhood to each other could be replaced by —NR^(45″)—, —O—, —S—,—C(═O)—O—, or, —O—C(═O)—O—, and/or wherein one or more hydrogen atomscan be replaced by F, a C₆-C₂₄aryl group, or a C₆-C₂₄aryloxy group,wherein one or more carbon atoms can be replaced by O, S, or N and/orwhich can be substituted by one or more non-aromatic groups R⁴¹, andR^(45″) is a C₁-C₂₅ alkyl group, or a C₄-C₁₈ cycloalkyl group.